* Changed LastPlayed field from string to nullable DateTime
Added ApplicationData.LastPlayedString property
Added NullableDateTimeConverter for the DateTime->string conversion in Avalonia
* Added migration from string-based last_played to DateTime-based last_played_utc
* Updated comment style
* Added MarkupExtension to NullableDateTimeConverter and changed its usage
Cleaned up leftover usings
* Missed one comment
* Ava UI: Expose games build ID for cheat management
* Fix bad merge
* Change integrity check level to error on invalid
* Add support for GDK
* Remove whitespace
* Add BID identifier
* PR Comments fix
* Restore title id in cheats GTK window
* use halign center instead of margin_left
* Merge
* fix after merge
* PR comments fix - design AVA
* PR fix - Move GetApplicationBuildId to ApplicationData class
* PR comment fix - Add empty line before method
* Align with PR #4755
* PR comments fix
* Change BuildId label to support translation
* Comments fix
* Remove unused BuildIdLabel property
