Bootstrap NativeAOT rewrite

[slxdy]

Introducing a new bootstrap and proxy fully made in .NET 9 with NativeAOT.

• 2x smaller output size
• The bootstrap and proxy are now a single project/module.
• Preload (.NET Standard 2.0 support) has been moved to the bootstrap itself.
• Project structure cleanup
• Dobby is now statically linked to the bootstrap

Todo

• Implement global logger in bootstrap
• Add bootstrap debug logs
• Implement automatic .NET 6 runtime installation
• Add win-x86 support
• Add linux-x64 support
• Merge Il2CppAssetBundleManager and Il2CppImageConversionManager into this repo
• Update README (credits etc.)

Future possibilities

A bootstrap in NativeAOT would add the ability to use Avalonia. I still haven't checked if it's possible to hook Avalonia into an existing game window, but it may be possible to create a new loading screen using it. Besides that, it would allow us to add other UI features, such as custom error boxes, custom console windows, runtime MelonPreferences manager, etc.

These ideas are outside the scope of this PR, but just a few examples of the possibilities for the future.

[slxdy]

Hm, PR workflows don't have access to the DEVVERSION repo variable. Should look into that.

[slxdy]

@HerpDerpinstine May I get the approval for the next point on the todo list?

[slxdy]

.NET 9 has just officially released, which is perfect timing. .NET 10 contains a breaking change that blocks DllMain, so we're good until it's necessary to switch