viewer: migrate to vue 3, general refactoring and cleanup

Non-exhaustive list of fixes and improvements done at the same time:

- html default background to grey (avoids white flash during init)
- unified links behavior
- added more theme variables
- removed the flex-expand transition (it wasn't working) and replaced it
  with a slide
- fixed LdLoading not centered on the content
- title on removable tags
- fixed an issue with encoded URI from vue-router
- unified Item resource URLs
- removed the iframe for PlainTextViewer (it wasn't working properly)
  and replaced it with a pre
- fixed clear and search buttons tabindex
- fixed the information panel bumping up during the fade animation of
  tag's dropdown
- fixed some focus outlines not appearing correctly
- moved CSS variables to the :root context
- Code cleaning

GitHub: closes #217
GitHub: closes #300
GitHub: closes #297
GitHub: closes #105
GitHub: closes #267
GitHub: closes #275
GitHub: closes #228
GitHub: closes #215
GitHub: closes #112

10 files changed, 73 insertions, 202 deletions

diff --git a/viewer/src/plugins/asyncLib.ts b/viewer/src/plugins/asyncLib.ts
new file mode 100644
index 0000000..de4f7ee
--- /dev/null
+++ b/viewer/src/plugins/asyncLib.ts
@@ -0,0 +1,3 @@
+
+export const importFaIcon = async() => (await import(/* webpackChunkName: "icons" */ '@fortawesome/vue-fontawesome')).FontAwesomeIcon;
+export const importHammer = async() => import(/* webpackChunkName: "hammer" */'hammerjs');
diff --git a/viewer/src/plugins/buefy.ts b/viewer/src/plugins/buefy.ts
deleted file mode 100644
index 4794ad9..0000000
--- a/viewer/src/plugins/buefy.ts
+++ /dev/null
@@ -1,48 +0,0 @@
-/* ldgallery - A static generator which turns a collection of tagged
---             pictures into a searchable web gallery.
---
--- Copyright (C) 2019-2020  Guillaume FOUET
---
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU Affero General Public License as
--- published by the Free Software Foundation, either version 3 of the
--- License, or (at your option) any later version.
---
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU Affero General Public License for more details.
---
--- You should have received a copy of the GNU Affero General Public License
--- along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-import Vue from "vue";
-
-// @ts-ignore
-import Taginput from "buefy/src/components/taginput";
-// @ts-ignore
-import Loading from "buefy/src/components/loading";
-// @ts-ignore
-import Button from "buefy/src/components/button";
-// @ts-ignore
-import SnackBar from "buefy/src/components/snackbar";
-// @ts-ignore
-import Tag from "buefy/src/components/tag";
-// @ts-ignore
-import DropDown from "buefy/src/components/dropdown";
-
-import "@/assets/scss/buefy.scss";
-
-Vue.use(Taginput);
-Vue.use(Loading);
-Vue.use(Button);
-Vue.use(SnackBar);
-Vue.use(Tag);
-Vue.use(DropDown);
-
-declare module "vue/types/vue" {
-  interface Vue {
-    $buefy: any;
-  }
-}
diff --git a/viewer/src/plugins/devServer.js b/viewer/src/plugins/devServer.js
new file mode 100644
index 0000000..2cccbbb
--- /dev/null
+++ b/viewer/src/plugins/devServer.js
@@ -0,0 +1,53 @@
+/* ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2019-2022  Guillaume FOUET
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/*
+-- Create a file .env.development.local in the project to customize your DevServer
+-- VUE_APP_DEVSERVER_CONFIG_PATH=<http_url> will use the dev_proxyconfig
+-- VUE_APP_DEVSERVER_CONFIG_PATH=<fs_path> will use the dev_fsconfig
+*/
+
+const devReady = Boolean(process.env.VUE_APP_DEVSERVER_CONFIG_PATH);
+const devIsProxy = devReady && Boolean(process.env.VUE_APP_DEVSERVER_CONFIG_PATH?.match(/^https?:\/\//i));
+const devLocalpath = `^/${process.env.VUE_APP_DATA_URL}`;
+const devProxyconfig = {
+  [devLocalpath]: {
+    target: process.env.VUE_APP_DEVSERVER_CONFIG_PATH,
+    pathRewrite: { [devLocalpath]: '' },
+  },
+};
+
+function devFsConfig(middlewares, devServer) {
+  devServer.app.get(`${devLocalpath}*`, (req, res) => {
+    const fs = require('fs');
+    const url = req.url.slice(process.env.VUE_APP_DATA_URL?.length);
+    const paramIdx = url.indexOf('?');
+    const filepath = paramIdx < 0 ? url : url.substring(0, paramIdx);
+    const fullpath = `${process.env.VUE_APP_DEVSERVER_CONFIG_PATH}${decodeURIComponent(filepath)}`;
+    const file = fs.readFileSync(fullpath);
+    res.end(file);
+  });
+  return middlewares;
+}
+
+module.exports = {
+  port: process.env.VUE_APP_DEVSERVER_PORT,
+  proxy: devReady && devIsProxy ? devProxyconfig : undefined,
+  setupMiddlewares: devReady && !devIsProxy ? devFsConfig : undefined,
+};
diff --git a/viewer/src/plugins/dragscroll.ts b/viewer/src/plugins/dragscroll.ts
deleted file mode 100644
index a10b0fd..0000000
--- a/viewer/src/plugins/dragscroll.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-/* ldgallery - A static generator which turns a collection of tagged
---             pictures into a searchable web gallery.
---
--- Copyright (C) 2019-2020  Guillaume FOUET
---
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU Affero General Public License as
--- published by the Free Software Foundation, either version 3 of the
--- License, or (at your option) any later version.
---
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU Affero General Public License for more details.
---
--- You should have received a copy of the GNU Affero General Public License
--- along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-import Vue from "vue";
-import VueDragscroll from "vue-dragscroll";
-
-Vue.use(VueDragscroll);
diff --git a/viewer/src/plugins/fontawesome-icons.ts b/viewer/src/plugins/fontawesome-icons.ts
deleted file mode 100644
index 4b50641..0000000
--- a/viewer/src/plugins/fontawesome-icons.ts
+++ /dev/null
@@ -1,45 +0,0 @@
-/* ldgallery - A static generator which turns a collection of tagged
---             pictures into a searchable web gallery.
---
--- Copyright (C) 2019-2020  Guillaume FOUET
---
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU Affero General Public License as
--- published by the Free Software Foundation, either version 3 of the
--- License, or (at your option) any later version.
---
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU Affero General Public License for more details.
---
--- You should have received a copy of the GNU Affero General Public License
--- along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-export {
-  faFolder,
-  faFolderOpen,
-  faEraser,
-  faSearch,
-  faPlus,
-  faMinus,
-  faImage,
-  faHome,
-  faArrowLeft,
-  faLevelUpAlt,
-  faAngleRight,
-  faAngleDoubleLeft,
-  faFile,
-  faFileAlt,
-  faFilePdf,
-  faFileVideo,
-  faFileAudio,
-  faFileDownload,
-  faCaretUp,
-  faCaretDown,
-  faAngleDoubleDown,
-  faSortAmountDown,
-} from "@fortawesome/free-solid-svg-icons";
-
-export { faCircle, faDotCircle } from "@fortawesome/free-regular-svg-icons";
diff --git a/viewer/src/plugins/fontawesome.ts b/viewer/src/plugins/fontawesome.ts
deleted file mode 100644
index 25ddd99..0000000
--- a/viewer/src/plugins/fontawesome.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-/* ldgallery - A static generator which turns a collection of tagged
---             pictures into a searchable web gallery.
---
--- Copyright (C) 2019-2020  Guillaume FOUET
---
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU Affero General Public License as
--- published by the Free Software Foundation, either version 3 of the
--- License, or (at your option) any later version.
---
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU Affero General Public License for more details.
---
--- You should have received a copy of the GNU Affero General Public License
--- along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-import Vue from "vue";
-
-import { library, config } from "@fortawesome/fontawesome-svg-core";
-import { FontAwesomeIcon } from "@fortawesome/vue-fontawesome";
-import * as faIcons from "./fontawesome-icons";
-
-library.add(faIcons);
-
-config.autoAddCss = false;
-import "@fortawesome/fontawesome-svg-core/styles.css";
-