Do not force a reconnection when adding or removing streams to a connection

[danxuliu]

When publishing permissions change, or when a call is started without an audio or video device and then the device is selected during the call, WebRTC connections need to be updated to add or remove the media streams. This requires a renegotiation, which is not currently implemented (and it would need to be implemented by all clients). As a workaround when media streams need to be added or removed for now a forced reconnection is triggered: the participant leaves and joins the call again, which recreates the connection with the new streams.

A forced reconnection may not be needed since strukturag/nextcloud-spreed-signaling@707b125 when the HPB is used and publishing permissions are revoked, as the HPB will automatically close the connections, but this needs to be tested. In any case a forced reconnection will still be needed for the other cases, so at some point renegotiation should be implemented.

Steps:

• nextcloud-spreed-signaling and Janus changes (signaling >= v0.5.0 and Janus >= 0.12.4 are needed)
• Adjustments for renegotiations talk-ios#725
• 🔁 Adjustments for renegotiations talk-android#1815
• Use renegotiations to update publisher connections #6896
• Add proactive establishment of connections when call flags change in mobile apps (Do not force reconnections when starting and stopping media #6934 for mobile apps)
• Do not force reconnections when starting and stopping media #6934