.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

VocaluxeLib/Keys.cs

@@ -0,0 +1,161 @@
+#region license
+// This file is part of Vocaluxe.
+// 
+// Vocaluxe is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// Vocaluxe is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with Vocaluxe. If not, see <http://www.gnu.org/licenses/>.
+#endregion
+
+using System;
+
+namespace VocaluxeLib
+{
+    [Flags]
+    public enum Keys
+    {
+        None = 0,
+        Back = 8,
+        Tab = 9,
+        Clear = 12,
+        Enter = 13,
+        Return = 13,
+        ShiftKey = 16,
+        ControlKey = 17,
+        Menu = 18,
+        Pause = 19,
+        CapsLock = 20,
+        Escape = 27,
+        Space = 32,
+        PageUp = 33,
+        PageDown = 34,
+        End = 35,
+        Home = 36,
+        Left = 37,
+        Up = 38,
+        Right = 39,
+        Down = 40,
+        PrintScreen = 44,
+        Insert = 45,
+        Delete = 46,
+        D0 = 48,
+        D1 = 49,
+        D2 = 50,
+        D3 = 51,
+        D4 = 52,
+        D5 = 53,
+        D6 = 54,
+        D7 = 55,
+        D8 = 56,
+        D9 = 57,
+        A = 65,
+        B = 66,
+        C = 67,
+        D = 68,
+        E = 69,
+        F = 70,
+        G = 71,
+        H = 72,
+        I = 73,
+        J = 74,
+        K = 75,
+        L = 76,
+        M = 77,
+        N = 78,
+        O = 79,
+        P = 80,
+        Q = 81,
+        R = 82,
+        S = 83,
+        T = 84,
+        U = 85,
+        V = 86,
+        W = 87,
+        X = 88,
+        Y = 89,
+        Z = 90,
+        LWin = 91,
+        RWin = 92,
+        Apps = 93,
+        NumPad0 = 96,
+        NumPad1 = 97,
+        NumPad2 = 98,
+        NumPad3 = 99,
+        NumPad4 = 100,
+        NumPad5 = 101,
+        NumPad6 = 102,
+        NumPad7 = 103,
+        NumPad8 = 104,
+        NumPad9 = 105,
+        Multiply = 106,
+        Add = 107,
+        Separator = 108,
+        Subtract = 109,
+        Decimal = 110,
+        Divide = 111,
+        F1 = 112,
+        F2 = 113,
+        F3 = 114,
+        F4 = 115,
+        F5 = 116,
+        F6 = 117,
+        F7 = 118,
+        F8 = 119,
+        F9 = 120,
+        F10 = 121,
+        F11 = 122,
+        F12 = 123,
+        F13 = 124,
+        F14 = 125,
+        F15 = 126,
+        F16 = 127,
+        F17 = 128,
+        F18 = 129,
+        F19 = 130,
+        F20 = 131,
+        F21 = 132,
+        F22 = 133,
+        F23 = 134,
+        F24 = 135,
+        NumLock = 144,
+        Scroll = 145,
+        LShiftKey = 160,
+        RShiftKey = 161,
+        LControlKey = 162,
+        RControlKey = 163,
+        LMenu = 164,
+        RMenu = 165,
+        VolumeMute = 173,
+        VolumeDown = 174,
+        VolumeUp = 175,
+        MediaNextTrack = 176,
+        MediaPreviousTrack = 177,
+        MediaStop = 178,
+        MediaPlayPause = 179,
+        OemSemicolon = 186,
+        Oemplus = 187,
+        Oemcomma = 188,
+        OemMinus = 189,
+        OemPeriod = 190,
+        OemQuestion = 191,
+        Oemtilde = 192,
+        OemOpenBrackets = 219,
+        OemPipe = 220,
+        OemCloseBrackets = 221,
+        OemQuotes = 222,
+        OemBackslash = 226,
+        KeyCode = 0x0000FFFF,
+        Shift = 0x00010000,
+        Control = 0x00020000,
+        Alt = 0x00040000,
+        Modifiers = unchecked((int)0xFFFF0000)
+    }
+}