Bug 469299

# SUMMARY
I just performed a new install from scratch on a new system, using Wayland.

When I started playing games, I noticed that compositing and desktop effects were not automatically disabled during the game, as was the case in my previous system (same KDE version, but on Xorg + Nvidia). This makes gaming on KDE+Wayland very unpleasant, since things like screen edges and desktop effects are still active.

This is linked to the fact that the configuration option "Allow applications to block compositing" is missing on Wayland.
My old and new compositor settings can be seen here: https://www.reddit.com/r/kde/comments/135z1bz/

# STEPS TO REPRODUCE
1. Fresh KDE install
2. Setup screen edges effects (e.g. show desktop in a corner)
3. Open a fullscreen game which should block compositing and effects (this works in Xorg)
4. See that effects are still active (e.g.: show desktop is still active)

# OBSERVED RESULT
On Wayland, compositing and effects are active during full-screen gaming, even if the game provides an hint to disable compositing.
This interferes with gaming, introducing performance degradation and causing interruptions during the game.

Notifications also seem not to be blocked (again, this was not an issue on Xorg).

# EXPECTED RESULT
Compositing and effects are inactive and do not interfere during full-screen gaming, if the game provides a hint to disable compositing.

# SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9
Kernel Version: 6.2.13-arch1-1 (64-bit)
Graphics Platform: Wayland
ADDITIONAL INFORMATION

Output of `qdbus org.kde.KWin /KWin org.kde.KWin.supportInformation`: https://pastebin.com/P1CwVEAA