Manual Explore Rooms

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.