A ground-up rewrite of SpriteGallery

Requires .NET 8.0

New features

• Cross-platform Avalonia-based UI, now should run on Linux (x86/amd64) and macOS (x64/arm). Currently untested
• Better bundle loading based on UnityDataTools
• Loads bundle dependencies
• BlueprintReferencedAssets for all bundles
• Works with Warhammer 40K: Rogue Trader and Pathfinder: Wrath of the Righteous

Currently missing or planned (WIP)

• Sprite atlas viewer