Advanced installer rework

[Al12rs]

Closes #750 .
This PR completely reworks the Advanced Manual installer code to follow the UI Coding Guidelines, as well as solving a number of other issues:

Addressed problems:

• Move the AdvancedInstaller.cs file to the main AdvancedInstaller project instead of in the AdvancedInstaller UI project.
• Installer breaks in CLI settings. Add implementation of the installer that is CLI compatible (return nothing -> fail). Use DI to get the UI version in UI setting.
• Remove the use of generics in AdvancedInstaller.cs, either use DI instead or just remove the need from the testing side.
• Use a Window instead of an Overlay. This is to allow moving and resizing the window, which was problematic on size constrained displays.
• Adopt the new UI Coding Guidelines.
• Restructure the code to be centralized in the main BodyVM, all other VMs should simple data containers with as little logic.
• Solve problem of not being able to access required data or objects from the scattered code.
• Reduce the number of Views and VMs by compacting them.
• Remove the code that populates Suggested Locations from the FileSystem. Instead populate using LocationIds.
• Use Dynamic Data flat trees for all the used ViewModel tree structures.
• Rename the three ITreeEntryVM to differentiate them.
• Use Optional values instead of Nullable.
• Cleanup namespaces and reorganize the code files.
• Rework the Tests for the new code.
• Properly comment the code.

Added features missing in previous version:

• Duplicated folder Pill.
• Folder merged Pill.
• Make Suggested Locations clearer.
• Show nested LocationIds in the Suggested section (e.g. Data for bethesda games)
• Auto focus on the the editing box after pressing Create Folder Button.
• Auto expand newly created folders.
• Save created folder on pressing ENTER.
  Scroll down to the created folder entry. (SKIPPED)
• Auto Expand new entries in Preview view (matching ModContent expanded state).
• Show trees selected item for keyboard navigation.
• Change color of expander chevron during hover, to give visual feedback of interaction area.
• Increase hitbox for expander interaction.
• Expand ModContent folders on pressing the Install button to select them for mapping.

Additional Changes:

• Fixed some Button Text alignment and cutoff.
• Don't show failed mod mod install entry in Loadout in case of user cancelling installation.
• Fix Create Folder button allowing the creation of duplicated folder names.
• Remove Window TitleBar while keeping window move functionality (needs testing on non Windows os).
• Use a single tree with multiple roots instead of multiple trees with a single root.
• Fixed Suggested Locations subtitle being wrong.
• Add Optional.ValueOr(Value) extension method, to avoid valueSelector action overhead.
• Comments and cleanup
• Review/Fix Tests.

TODO:

• Update tests after Paths library changes are merged in to test case changes

[erri120]

We should do a squash merge.

[codecov-commenter]

Codecov Report

Merging #790 (772518e) into main (0af4b76) will decrease coverage by 1.12%.
Report is 32 commits behind head on main.
The diff coverage is 60.28%.

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #790      +/-   ##
==========================================
- Coverage   63.38%   62.26%   -1.12%     
==========================================
  Files         585      594       +9     
  Lines       17869    18580     +711     
  Branches     1254     1324      +70     
==========================================
+ Hits        11326    11569     +243     
- Misses       6203     6658     +455     
- Partials      340      353      +13     

Flag	Coverage Δ
Linux	61.67% <60.28%> (-1.06%)	⬇️
Windows	61.49% <60.28%> (-1.11%)	⬇️
clean_environment_tests	62.25% <60.28%> (-1.12%)	⬇️
network_tests	?

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

Files	Coverage Δ
...Content/TreeEntry/IModContentTreeEntryViewModel.cs	100.00% <100.00%> (ø)
...ht/Preview/TreeEntry/IPreviewTreeEntryViewModel.cs	100.00% <100.00%> (ø)
...ocation/TreeEntry/ISelectableTreeEntryViewModel.cs	100.00% <100.00%> (ø)
...dvancedInstaller.UI/Resources/Language.Designer.cs	6.94% <100.00%> (-2.28%)	⬇️
...s/NexusMods.Games.AdvancedInstaller.UI/Services.cs	100.00% <100.00%> (ø)
...exusMods.Games.AdvancedInstaller/DeploymentData.cs	97.43% <100.00%> (ø)
...ames/NexusMods.Games.AdvancedInstaller/Services.cs	100.00% <100.00%> (ø)
...xusMods.Games.BethesdaGameStudios/ABethesdaGame.cs	100.00% <ø> (ø)
...aGameStudios/Exceptions/MissingMastersException.cs	0.00% <ø> (ø)
.../NexusMods.App.UI/Theme/ButtonStyles/Standard.xaml	97.43% <100.00%> (-0.24%)	⬇️
... and 28 more

... and 10 files with indirect coverage changes