Add the ability to set and show suggested rooms for spaces.
This is just adding the basic functionality, we can do more things with it later like sort/filter the space home for example.
Add a space homepage with the ability to both create new room and add existing rooms to the space. This uses a tree model for the space hierarchy and will go to any number of levels. The user should only see the add options if they have appropriate permissions.
This MR also combines the create space and room pages and adds a lot of optional functionality for managing space children.
