tiling: Add option to lock tiling layout
Some users prefer that resizing tiled windows makes them float and to be able to re-tile them later to the previous layout. (This was the default in Plasma < 5.27, Windows 7 and is in Xfce)
Additionally, allow the opposite action to be triggered on the fly by holding shift on resize. Custom tiling already uses shift on move. (Windows 10 uses CTRL to break snapped-together resizing temporarily)
The new setting is in Window Management > Advanced.
Other places didn't seem to be as fitting because in all cases when you
can disable a tiling-related option, quick-tiling shortcuts and custom
tiling shift+move still stay active:
- Screen edge settings: You can only disable electric border tiling.
- Tiling manager overlay or effect config: Is unavailable when Tiling manager effect is disabled.
The flicker resize fix is needed because the tiling layout lock makes it much more prominent.
Edited by Erwin Saumweber