Implemented localization support throughout the app

[Al12rs]

closes #453

• Implemented translations for relevant strings in the app using backed implemented with Implement the translation backend #452
• Localized strings should update themselves live on language change for the most part, or close enough in some cases.
• I did not test live updating as we discussed it wasn't a hard requirement.
• Added a way to create avalonia bindings in code for localized strings and added documentation for that use case.
• Added rough but serviceable Italian translation, which I used to test the if translations were working.
• Reduced some of the flakyness of Localization tests by making them sequential and resetting the locale to English after each test.
• The ui related localization test are still flaky due to accessing ui from wrong thread or something.
• Fixed a DownloadTaskViewModel test that didn't work after the localization changes due to there being an additional Poll() call in the viewModel constructor now.

I tried finding all of the string, but I might have missed some.

[codecov]

Codecov Report

Merging #587 (c05db36) into main (8fce8a0) will decrease coverage by 0.27%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main     #587      +/-   ##
==========================================
- Coverage   68.12%   67.85%   -0.27%     
==========================================
  Files         599      599              
  Lines       16222    16465     +243     
  Branches     1086     1098      +12     
==========================================
+ Hits        11051    11173     +122     
- Misses       4895     5010     +115     
- Partials      276      282       +6     

Flag	Coverage Δ
Linux	67.09% <50.00%> (-0.30%)	⬇️
Windows	66.94% <50.00%> (-0.32%)	⬇️
clean_environment_tests	67.85% <50.00%> (-0.26%)	⬇️
network_tests	?
networking_tests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage
...Controls/Buttons/RoundedButton/RoundedButton.axaml	0.00%
...usMods.App.UI/Controls/GameWidget/GameWidget.axaml	0.00%
src/NexusMods.App.UI/Controls/Pills/Premium.axaml	0.00%
...p.UI/LeftMenu/Items/LaunchButtonDesignViewModel.cs	ø
...ys/Download/Cancel/CancelDownloadOverlayView.axaml	0.00%
...Download/Cancel/CancelDownloadOverlayView.axaml.cs	0.00%
....App.UI/Overlays/Login/NexusLoginOverlayView.axaml	0.00%
....App.UI/RightContent/Downloads/CompletedView.axaml	0.00%
...ds.App.UI/RightContent/Downloads/HistoryView.axaml	0.00%
.../NexusMods.App.UI/RightContent/Home/HomeView.axaml	0.00%
... and 19 more

[halgari]

This is a lot of mind-numbing work. Thanks for cranking through all this code.