This makes KWin switch to in-tree copy of KWaylandServer codebase.
KWaylandServer namespace has been left as is. It will be addressed later
by renaming classes in order to fit in the KWin namespace.
The .clang-format file is based on the one in ECM except the following
style options:
- AlwaysBreakBeforeMultilineStrings
- BinPackArguments
- BinPackParameters
- ColumnLimit
- BreakBeforeBraces
- KeepEmptyLinesAtTheStartOfBlocks
There was no handling for the drop being cancelled at all, leading to
leaked WlVisit and XtoWlDrag objects. X clients could also be confused
about the state of the drag and for example not being able to start another
drag.
BUG:449362
