Move favorites to home screen
This allows moving the app drawer to the home screen so the app drawer (!187 (closed)) doesn't have to fight against duplicte arrows, etc.
WIP since this builds upon !262 (merged) and !263 (merged) and we might just want to drop the last patch in this series and use a reworked !187 (closed) right away.
Also the running apps list is currently broken since the current widget only fetches it once but since @sebastian.krzyszkowiak works on #37 (closed) this will fix itself once tht is merged (and we have a PhoshToplevelManager
).
Closes: #89 (closed), #99 (closed), #142 (closed)