Rework roommanager for improved stability
Fixes #645 (closed)
- Active space handling is moved from QML to RoomManager
- Active tab in SpaceDrawer (space / no space / DM) is unified in a single variable
- RoomList & RoomPage loading is simplified: We're always pushing a RoomPage now; if there is no room, a placeholder is shown
- SpaceHomePage is moved into RoomPage; This replaces the entire push/replace room/spacehome logic
- If the current room is a space, the space home is shown, otherwise the timeline
- The concept of "previous room" is removed entirely. If we're leaving the active room, the placeholder room page is shown
- When clicking on a space in the list, the space room list is switched and the space home page is shown
In short, these changes should (after some initial regressions) lead to a less crashy NeoChat :)