feat: Add a colibri2 notification IQ.

[bgrozev]

No description provided.

[savely-krasovsky]

I was about to open own PR with custom IQ to start/stop transcribation :) This seems to be more versatile. Any plans to merge it soon?

[savely-krasovsky]

@bgrozev but I am not sure how it is/was supposed to work. From what I see both Jibri and JVB doesn't emit their own IQs, they only listen and respond to them. This ConferenceNotificationIQ at least seems like the way to query Jicofo from JVB and wait an "ack" from it. Like "there is a problem with ICE, I am notifying you, please acknowledge". meetingId property supports this theory, because from my understanding this is the only way for Jicofo to know with which conference the problem occurred and update presence (to notify actual users). But I don't see any infrastructure for now to send stanzas from JVB to Jicofo. I am missing some Jicoco's mucclient update?

[savely-krasovsky]

This init seems to be unnecessary causing duplicating of extensions (addNotification already calls addExtension method).

[savely-krasovsky]

By working more with JVB and Jicofo codebases this IQ seems more about pull-mode. Jicofo would poll JVBs for available Notification's and act accordingly (by sending updated presense for example). I am correct?

[Neustradamus]

@bgrozev, @savely-krasovsky: Any progress on it?