Port to function-pointer based QMetaObject::invokeMethod
It's more efficient and compile-time checked
Especially for stuff that's done loads on startup (e.g. the effectloader stuff or decoration on kwin_x11 restart)
There's a few left but I only ported the ones I could actually test:
- window decos still work on startup, opening a client, after unminimize borderless-maximized window
- can still close window through title bar menu (user actions) and decoration close button
- can still minimize/maximize through title bar menu
- animated and normal effects still load
- gl freeze protection timer is triggered