Add Zephyr bridging to existing rooms

[gabrc52]

There doesn't seem to be a straightforward to add Zephyr bridging to existing rooms:

1. (Workaround) Disable the app service on the homeserver's settings, then add the CANONICAL alias to the rooms you wish to link to Zephyr, then re-enable the app service. (Or maybe it's just Element not letting you, since it checks if aliases are available before creating them.). But then due to it trying to read the room state using the main appservice token and not a ghost, it fails to find what room it is, so you need to add the bot and join it so it can read the state. Looks like it's done? No! you need to manually subscribe the other half by zwriting daemon/matrix.mit.edu an add class instance * or editing zephyr.subs and restarting that half of the bridge.

2. We could break the convention that class names and instance names have a specific format and add a config flag to override the room for specific pairs of classes and instances

3. (Better) We could do 1, but in a way that both aliases are kept, so the code should be modified so it doesn't just read Matrix canonical aliases. So the room could have 2 aliases, one that follows our convention and one that doesn't.

[gabrc52]

Yeah uh it should be more like 1) add the bot, 2) send a command, 3) done

[gabrc52]

Oh and you forgot that you have to invite and join the bot 😭

edit: actually the matrix homeserver might push events to the appservice even without the account in the room, unsure, would have to experimentally verify or read the spec