[MatrixRTC] Sticky Events support (MSC4354)

[toger5]

Depends on #5028

This PR adds support for sticky events in the MatrixRTCSession:

• send sticky events instead of state events
• update the call memberships based on sticky events instead of membership changes.
• resend the current membership if the sticky event times out with an updated expiration ts (This is not the final solution. the sticky event timeout in iteself is enough. no expiration needed on the event content)

[toger5]

temp review

[toger5]

Wondering if we really want to make this configurable?
It would be great if we can just always make it listen to this?
Not sure its possible however...
Do you have an idea for a case where "always on" would break?

[toger5]

this in combination with:
this.roomSubset.on(RoomEvent.StickyEvents, this.onStickyEventUpdate);
will result in two calls to recalculateSessionMembers once via refreshRoom -> onRTCSessionMemberUpdate -> recalculateSessionMembers And a second time throughonStickyEventUpdate->`recalculateSessionMembers.

Or is there any check so one of them gets ignored?

A possible solution would be to check if the associated room already has a session (in onRoom) and if so, we do not call refresh room? So it only gets called on creating a new session?

This logic maybe should be applied to all of this file. refreshRoom should be: refreshSessionStore/Map and than we expect the session itself to listen to all the evnt updates. Listeners in the SessionManager only are responsible to find out if new sessions need to be created!

[toger5]

I am relativly sure we are doing the right thing.
But I want to write down (and get confirmation) that we do expire call memberships if the sticky duration times out

• Once a sticky event expires we emit the sticky map change action
• if that action is emitted we recalculate the room
• public static sessionMembershipsForSlot will get called as a consequence
• this method will compute all the memberships based on the CURRENT SET OF matrix sticky events? (so if some event times out, it will not be in the CURRENT SET OF matrix sticky and hence will not be aprt of the memberships anymore?

[Half-Shot]

This test suite needs much expanding really. This only touches the joins, we really need to test other behaviours.

[toger5]

The only thing that this class does really is overwriting send and send delay + makeMyMembership. All this is covered in the join test.
There is also the error logging method... but that not being tested sounds fairly save.

All the rest of the behavior of the Memberhsip Manager stays as it was.

[toger5]

Is there anything specific you have in mind?

[Half-Shot]

I'd just make this a static const, which gives you types for free and stops us creating a new Map each time we call this.

[toger5]

yes that makes sense.

[Half-Shot]

Otherwise LGTM