Hide public rooms from list endpoint

[sampaccoud]

Purpose

Currently, public rooms are listed on every users' dashboard. Although we want every user be able to join a public room, we don't want them to see it in their personal list of rooms.

We want rooms to be private by default (even better make it configurable via settings)

Finally, the Jitsi parameter to start with audio muted does not work.

Proposal

• [x] Filter out public rooms on rooms' list API endpoint. Fixes https://github.com/openfun/jitsi-magnify/issues/208
• [x] Add a new setting DEFAULT_IS_PUBLIC to determine if a room is public or private by default
• [x] Fix typo on the parameter to start with audio muted

[Moustique82]

link with issu 208 https://github.com/openfun/jitsi-magnify/issues/208