MyGUI 3.5.4

Tools and demos

• Fix SDL key mappings for apostrophe and numpad Enter
• Use mouse-button event coordinates for presses and releases, avoiding theoretical stale positions from the last mouse
  move

Infrastructure

• Fix compilation with MSVC 2022 and add CI coverage for this toolset (#331)
• Fix builds with newer Emscripten when high-level warnings are enabled
• Build and run platform tests in every CI build-matrix job, including static builds
• Cache vcpkg dependency binaries between Windows CI runs