Currently, classes like `Workspace`, `X11Client`, `AbstractClient`, `Unmanaged`, and `Group` are spread among multiple topic cpp files. The worst thing about this is that we are not consistent about how topics are split. One such example is geometry code, some stuff is in abstract_client.cpp, and the other stuff is in geometry.cpp.
In order to make kwin's code base readable and easier to work with, we need to split all topic cpp files.
The list of topic files:
[ ] activation.cpp
[ ] events.cpp
[ ] geometry.cpp
[x] group.cpp: D25713
[ ] layers.cpp
[x] manage.cpp: D25712
[ ] placement.cpp
[ ] useractions.cpp
Files `composite.{h,cpp}` most likely need to be renamed to `compositor.{h,cpp}`