Add new packages and build scripts for various libraries

- Added Nuklear GUI library with build script and configuration.
- Introduced OpenH264 encoder/decoder with build configuration.
- Added PortAudio library for audio I/O with custom build script.
- Included Python Execnet for multi-Python deployment.
- Added Pytest Xdist plugin for distributed testing.
- Introduced Shaderc for shader compilation tools.
- Added Snappy compression library with necessary patches and configuration.
- Included SoundTouch audio processing library with build configuration.
- Added SRT library for secure reliable transport.
- Introduced VapourSynth video processing framework with configuration.
- Added Vid.stab for video stabilization.
- Included WebRTC Audio Processing library with build configuration.
- Added X264 video encoding library with patches for POSIX compliance.
- Introduced X265 video encoder with build configuration.
- Added XKeyboard Config for X keyboard configuration files.
- Included Xorg XKBComp for keyboard description compilation.
- Added Xvidcore MPEG-4 video codec library with configuration.
- Introduced ZeroMQ messaging system with patches and build configuration.
- Added Zimg library for scaling and colorspace conversion.

extra/libxkbfile/libxkbfile.toml

@@ -0,0 +1,28 @@
+[build]
+type = "meson"
+
+[build.flags]
+build_dir = "build"
+
+[dependencies]
+build = [
+    "xorg-util-macros",
+    "meson",
+]
+runtime = [
+    "libx11",
+    "xorgproto",
+    "glibc",
+]
+
+[package]
+description = "X11 keyboard file manipulation library"
+homepage = "https://gitlab.freedesktop.org/xorg/lib/libxkbfile"
+license = "LicenseRef-libxkbfile"
+name = "libxkbfile"
+version = "1.2.0"
+
+[[source]]
+extract_dir = "$name-$version"
+sha256 = "7f71884e5faf56fb0e823f3848599cf9b5a9afce51c90982baeb64f635233ebf"
+url = "https://xorg.freedesktop.org/releases/individual/lib/$name-$version.tar.xz"