.NET10 Migration (#946)

Runtime and build
- Move all projects to .NET 10 with SDK-style project files and a shared
  Directory.Build.props (WIN/LINUX, x86/x64 defines)
- Load managed and unmanaged dependencies from libs/managed and
  libs/unmanaged through assembly and native library resolvers
- Compile party modes with Roslyn instead of CodeDom
- Update AppVeyor to the .NET 10 SDK and dotnet test
- Download the FFmpeg and gstreamer runtimes from the dependencies
  repository during the build
- Remove the VC++ 2015-2022 runtime check, no dependency needs it anymore

Graphics and windowing
- Replace the Direct3D 9 renderer with Direct3D 11 (Vortice)
- Pace Direct3D 11 frames with a frame latency waitable swap chain
- Move window, input and message boxes to SDL3
- Replace System.Drawing with SkiaSharp and WinForms with SDL3 and a
  software renderer

Video and audio
- Replace Acinerella with FFmpeg 8.1.3 (FFmpeg.AutoGen)
- Add hardware accelerated video decoding (D3D11VA, DXVA2, VideoToolbox,
  VAAPI, VDPAU) with software fallback
- Convert YUV video frames to RGB on the GPU in Direct3D 11 and OpenGL
- Add the video options HardwareDecoding, GpuColorConversion,
  DecoderThreads and VideoDownscaleResolution
- Update OpenAL to OpenTK 4 and NAudio recording to WasapiRecorder

Fixes
- Fix the song preview start and shorten the reporter buttons
- Fix a crash when opening the highscore without a selected song
- Use the options slide highlight in the party mode screens to avoid
  brightness flicker on VRR displays
- Disable GameInput in the x86 build, SDL3 crashes in GameInputCreate
  on 32-bit systems with the GameInput runtime installed
- Fix a truncation warning in PitchTracker

HowToBuildWin.md

@@ -9,7 +9,7 @@
   
   ![url](https://cloud.githubusercontent.com/assets/5115160/4995708/bc5af234-69c2-11e4-91d1-112972f35f01.PNG)
 
-* Make sure [Visual Studio 2012/2013(?)](http://www.visualstudio.com/downloads/download-visual-studio-vs#d-express-windows-desktop) is installed 
+* Make sure [Visual Studio 2026](https://visualstudio.microsoft.com/downloads/) with the workloads `.NET desktop development` and `Desktop development with C++` and the [.NET 10 SDK](https://dotnet.microsoft.com/download/dotnet/10.0) are installed
 
 * Make sure [Node.js (LTS)](https://nodejs.org) is installed. It is needed to build the WebApp (folder `WebApp`), which is built automatically together with the project `VocaluxeWeb`. Restart Visual Studio after installing it.