Add configuration files and patches for R, SDL2, SDL3, Tk, and Vala

- Introduced `r.toml` for R package configuration, including build flags and dependencies.
- Added `sdl2-compat.toml` for SDL2 compatibility layer with SDL3, specifying build and runtime dependencies.
- Created a patch for SDL3 to handle cases when XInput2 is not available, ensuring compatibility.
- Added `sdl3.toml` for SDL3 configuration, including build flags and dependencies.
- Introduced `tk.toml` for Tk configuration, detailing build flags and runtime dependencies.
- Added a patch for Vala to ensure POSIX compliance in the test runner script, improving portability.

extra/r/r.desktop

@@ -0,0 +1,11 @@
+[Desktop Entry]
+Name=R
+GenericName=environment for statistical computing
+Comment=language and environment for statistical computing and graphics
+Exec=R
+Icon=/usr/share/pixmaps/r.png
+DocPath=/usr/lib/R/doc/html/index.html
+StartupNotify=true
+Terminal=true
+Type=Application
+Categories=Math;Science;Education