.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

.appveyor/runGitLink.ps1

@@ -1,13 +0,0 @@
-choco install gitlink --version 3.1.0-unstable0017 --pre --no-progress --limit-output
-
-Get-ChildItem -Path ".\Output" -Recurse "*.pdb" | %{    
-    If ($_.Fullname -contains 'PitchTracker.pdb'){
-        & gitlink -u "`"https://github.com/$($Env:APPVEYOR_REPO_NAME)`"" -a --baseDir "`"$Env:APPVEYOR_BUILD_FOLDER`"" --commit "`"$Env:APPVEYOR_REPO_COMMIT`"" "`"$($_.Fullname)`""
-    }
-    else{
-        & gitlink -u "`"https://github.com/$($Env:APPVEYOR_REPO_NAME)`"" --baseDir "`"$Env:APPVEYOR_BUILD_FOLDER`"" --commit "`"$Env:APPVEYOR_REPO_COMMIT`"" "`"$($_.Fullname)`""
-    }    
-}
-
-# srcsrv were integrated in the pdb files -> delete the srcsrv files
-Remove-Item ".\Output\*.pdb.srcsrv"