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

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 https://github.com/strukturag/nextcloud-spreed-signaling/commit/707b1257309f5ad66f6b67f9c0dc41eaa6f72532 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)
• https://github.com/nextcloud/talk-ios/issues/725
• https://github.com/nextcloud/talk-android/issues/1815
• https://github.com/nextcloud/spreed/pull/6896
• Add proactive establishment of connections when call flags change in mobile apps (#6934 for mobile apps)
• https://github.com/nextcloud/spreed/pull/6934