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

3 files changed, 0 insertions, 16 deletions

diff --git a/viewer/examples/config.json.example b/viewer/examples/config.json.example
deleted file mode 100644
index 580da8c..0000000
--- a/viewer/examples/config.json.example
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "galleryRoot": "gallery/"
-}
diff --git a/viewer/examples/defaulticon.png b/viewer/examples/defaulticon.png
deleted file mode 100644
index 0194e29..0000000
--- a/viewer/examples/defaulticon.png
+++ /dev/null
diff --git a/viewer/examples/manifest.json.example b/viewer/examples/manifest.json.example
deleted file mode 100644
index d07209f..0000000
--- a/viewer/examples/manifest.json.example
+++ /dev/null
@@ -1,13 +0,0 @@
-{
-  "short_name": "LdGallery",
-  "name": "LdGallery",
-  "icons": [
-    {
-       "src": "defaulticon.png",
-       "type": "image/png",
-       "sizes": "192x192"
-    }
-  ],
-  "display": "standalone",
-  "_comment": "https://developer.mozilla.org/en-US/docs/Web/Manifest"
-}