outputconfigurationstore: add new config system

Instead of an external service (like KScreen) storing and restoring output configurations,
with this commit KWin takes over that responsibility. This allows it to, among other things,
generate appropriate configs for new sets of outputs immediately, and take KWin-internal information
about outputs into account when generating them.

CCBUG: 474021
CCBUG: 469653
CCBUG: 466342
CCBUG: 470863
CCBUG: 466556
BUG: 466208
BUG: 455082
BUG: 457430