Pull the generic aspects from Room search and join room pages into it's own component. This is done in anticipation of using the new generic search page for a user search functionality.
- `SearchPage` is now used for the generic version with the old one being renamed `RoomSearchPage`
- `JoinRoomPage` is renamed to `ExploreRoomsPage` inline with everywhere else in NeoChat
There is also some cleanup of the code for both search pages in here.
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.
