Architecture / Modularization

After the InputCapture Portal implementation and being able to use input-leap/deskflow with Plasma 6 on Wayland, the session restore is one of the few big annoyances that I still have with Wayland. By now I still miss:

- That my apps remembers their size and position. It's very annoying to have all windows to show up stacked at the center of screen and always need to distribute them around my monitors and workspaces;
- Being able to Shade/Unshade windows. Reduce the windows to only its title bars is a very quick and convenient way to put an window "out of way" to see what is under it and then back to its place;
- Something to remember permissions that I gave for an application to do something (snapshot screen, read my keyboard, etc), I don't want to re-authorize things at every startup.

I am happy that it's a very small list.