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

1 files changed, 1 insertions, 1 deletions

diff --git a/viewer/ldgallery-viewer.7.md b/viewer/ldgallery-viewer.7.md
index 1e914ff..00435bc 100644
--- a/viewer/ldgallery-viewer.7.md
+++ b/viewer/ldgallery-viewer.7.md
@@ -161,7 +161,7 @@ The ldgallery source code is available on <https://ldgallery.pacien.org>.
 
 # LICENSE
 
-Copyright (C) 2019-2020  Pacien TRAN-GIRARD and Guillaume FOUET.
+Copyright (C) 2019-2022  Pacien TRAN-GIRARD and 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.