Had to add an email attribute to users to store their email to send the
notification. Will only send it for user rooms since they are the only
ones we know who to notify.
The endpoint receives events from BigBlueButton via webhooks or scripts
in the record and playback workflow.
For now it only treats the event for when a recording is ready.
When it happens, it uses action cable to update the interface dynamically
with the new recording.
Unlisted is a state between published and unpublished. They are still
published in the server, but will not appear to anyone other than the
user that created the recording.
It is done using a metadata attribute and required several changes in how
the application handles publishing and unpublishing.
