outputconfigurationstore: don't overwrite output settings with kscreen configs
The existing code overwrites all per-output data with the config from KScreen every time an output config is found that isn't in the KWin data base yet. That causes problems like the scale being reset to 1.0 if the user logged into Xorg before, or resetting it to whatever scale KScreen had saved on Wayland, which isn't much better.
Instead of doing that, use the KScreen config as inspiration for some specific output settings, instead of copying it outright. It's not ideal, but it's better than overwriting settings the user has explicitly set up