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/libical/libical.toml

@@ -0,0 +1,47 @@
+[build]
+type = "cmake"
+
+[build.flags]
+build_dir = "build"
+configure = [
+    "-G Ninja",
+    "-DGOBJECT_INTROSPECTION=true",
+    "-DICAL_GLIB_VAPI=true",
+    "-DSHARED_ONLY=true",
+    "-DCMAKE_DISABLE_FIND_PACKAGE_BerkeleyDB=true",
+    "-DICAL_BUILD_DOCS=False",
+]
+
+[dependencies]
+build = [
+    "cmake",
+    "ninja",
+    "vala",
+    "gobject-introspection",
+]
+runtime = [
+    "glibc",
+    "glib2",
+    "icu78",
+    "libunwind",
+    "libcxx",
+    "libxml215",
+]
+test = ["python-gobject"]
+
+[package]
+description = "open source reference implementation of the icalendar data type and serialization format"
+homepage = "https://github.com/libical/libical"
+license = [
+    "LGPL-2.1-only",
+    "MPL-2.0",
+]
+name = "libical"
+version = "3.0.20"
+
+[[source]]
+extract_dir = "$name-$version"
+url = "https://github.com/libical/libical.git#v$version"
+post_extract = [
+    "sed -i '/add_subdirectory(docs)/d' CMakeLists.txt",
+]