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.
So the original space parent and child stuff was technically a bit naughty in that it allowed multiple rooms to be set as the canonical parent. Because while a room can have multiple parents only one should be canonical. This adds the following:
- When adding a child or parent there is an extra check to select if the new parent should be canonical
- Any parent can be selected as the canonical one from the room settings
- All functions ensure that there is only ever one canonical parent by ensuring all others are false when a new one is set.
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.
