Both of this features listen for events in the XMPP connection. Thus, if we join
another meeting over the same connection we might still receive some events on
the old event handler.

Stop listening for events from the components as soon as the leave operation is
triggered.

This is necessary when adding new properties to the payload.

They are companion rooms created in a separate MUC. The room relationship is
maintained by a Prosody plugin.

All signalling happens through the breakout rooms MUC component.
Co-authored-by: Saúl Ibarra Corretgé <saghul@jitsi.org>