rGuiLayout v4.0

Official release for rGuiLayout v4.0. Some features on this release:

• ADDED: Target latest raygui 4.0 release.
• ADDED: Support macOS platform (x86_64 + arm64)
• REDESIGNED: Reference window definition
• REVIEWED: Controls palette panel
• REVIEWED: Layout code export window
• REVIEWED: Layout code generator (.c/.h)
• REVIEWED: Layout loading and saving (.rgl)
• REVIEWED: Regenerated tool imagery

Enjoy rGuiLayout!