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/libxkbcommon/libxkbcommon.toml

@@ -0,0 +1,42 @@
+[build]
+type = "custom"
+
+[dependencies]
+build = [
+    "meson",
+    "wayland",
+    "wayland-protocols",
+    "xkeyboard-config",
+    "xorgproto",
+    "libxcb",
+    "git",
+    "graphviz",
+    "doxygen"    
+]
+runtime = [ "glibc", "libxml215", "xkeyboard-config" ]
+optional = [ "wayland", "libxkbcommon-x11" ]
+
+[package]
+description = "Keymap handling library for toolkits and window systems"
+homepage = "https://github.com/xkbcommon/libxkbcommon.git"
+license = "MIT"
+name = "libxkbcommon"
+version = "1.13.1"
+
+[package_dependencies.libxkbcommon-x11]
+runtime = [
+    "glibc",
+    "libxcb",
+    "libxkbcommon",
+]
+
+[[packages]]
+description = "Keyboard handling library using XKB data for X11 XCB clients"
+homepage = "https://xkbcommon.org/"
+license = "MIT"
+name = "libxkbcommon-x11"
+version = "1.13.1"
+
+[[source]]
+extract_dir = "libxkbcommon"
+url = "https://github.com/xkbcommon/libxkbcommon.git#xkbcommon-$version"