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.
This is an update to searching the public room list. Currently if you can't find the room you're looking for you can type a full alias of room ID into the search bar and a view/join button appears. This is hard to discover and technically broken since it was turned into a generic component for finding rooms (it kinda works but doesn't fit now as it's focussed on the joining rooms not adding new ones to spaces). It is also not very discoverable if you don't know it's there.
This patch patch updates the workflow to be truly generic and hopefully more discoverable. Instead of using the search bar if no results are found a button asking if someone wants to manually enter a room ID or alias appears. This launches a dialog where the user can type in an alias or ID and it has some basic checking to make sure the string looks as expected.
The new functionality also generically works for joining rooms and adding children to spaces.
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.

It seems at some point in time the 16x16 tray icon got lost/hastily upscaled to a 22x22 tray icon,
which resulted in proportions as well as icon guidelines being slightly off.
This replaces the tray icon with a new one redrawn to adhere to icon guidelines and proportions closer
to the colour icon.
If you use your private keys (like when deleting the quotient database)
your session is broken as you have differing keys on the server. While
it is possible to work your way out of it, it's better to warn users to
bite the bullet and log in again.