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

2 files changed, 44 insertions, 26 deletions

diff --git a/viewer/src/locales/en.json b/viewer/src/locales/en.json
deleted file mode 100644
index d0a7a26..0000000
--- a/viewer/src/locales/en.json
+++ /dev/null
@@ -1,26 +0,0 @@
-{
-  "command.back": "Go back",
-  "command.parent": "Go to parent directory",
-  "command.search": "Open/close search panel",
-  "command.search.clear": "Clear",
-  "command.search.search": "Search",
-  "command.sort.byDateAsc": "By date (oldest first)",
-  "command.sort.byDateDesc": "By date (most recent first)",
-  "command.sort.byTitleAsc": "By title (A to Z)",
-  "directory.no-results": "Empty directory",
-  "download.download-file-fmt": "Download {0}",
-  "gallery.unknown-resource": "Resource not found",
-  "panelLeft.information.title": "Information",
-  "panelLeft.propositions": "Related filters",
-  "panelLeft.propositions.other": "other filters",
-  "search.no-result-fmt": "No result<br>({0} match in other folders) | No result<br>({0} matches in other folders)",
-  "snack.retry": "Retry",
-  "splashScreen.button.acknowledge": "Acknowledge",
-  "tag-propositions.addition": "Include all items with this tag",
-  "tag-propositions.intersection": "Search for this tag",
-  "tag-propositions.item-count": "Item count",
-  "tag-propositions.showmore": "show more ({0})",
-  "tag-propositions.substraction": "Exclude items with this tag",
-  "tagInput.nomatch": "No match",
-  "tagInput.placeholder": "Filters"
-}
diff --git a/viewer/src/locales/en.yml b/viewer/src/locales/en.yml
new file mode 100644
index 0000000..acbe24b
--- /dev/null
+++ b/viewer/src/locales/en.yml
@@ -0,0 +1,44 @@
+command:
+  back: Go back
+  parent: Go to parent directory
+  search:
+    clear: Clear
+    search: Search
+    slider: Open/close search panel
+  sort:
+    byDateAsc: By date (oldest first)
+    byDateDesc: By date (most recent first)
+    byTitleAsc: By title (A to Z)
+    title: Sort by...
+directory:
+  no-results: Empty directory
+download:
+  download-file-fmt: Download {0}
+gallery:
+  resource-loading-error: Error loading resource
+  unknown-resource: Resource not found
+panelLeft:
+  information:
+    title: Information
+  propositions:
+    other: other filters
+    related: Related filters
+  taglist:
+    activetag:
+      title: Remove tag
+search:
+  no-result-fmt: >-
+    No result<br>({0} match in other folders) | No result<br>({0} matches in
+    other folders)
+splashScreen:
+  button:
+    acknowledge: Acknowledge
+tag-propositions:
+  addition: Include all items with this tag
+  intersection: Search for this tag
+  item-count: Item count
+  showmore: show more ({0})
+  substraction: Exclude items with this tag
+tagInput:
+  nomatch: No match
+  placeholder: Filters