kwinoptions: disable AllowKDEAppsToRememberWindowPositions by default
This option creates a lot of confusion and inconsistency:
- it makes window placement ignore placement rules
- it makes window placement ignore the active screen
- it makes KDE apps behave differently from all other apps
- it has bugs with multi-monitor setups
- it makes the X11 session behave different from the Wayland session
Because of this confusion, our users are now using KWin scripts like "Always Open on Active Screen" (almost 100.000 downloads!) that enforce the behavior that KWin already applies to new windows.
Using such workarounds should not be necessary to get predictable window placement!