Not a fix. Mac sometimes crashes when destroying mItems in LLPersistentNotificationChannel
Decided to try cleaning mItems explicitly to see if it will change callstack, it won't fix the crash, but will help figuring out if source of the issue is in mItems or is LLPersistentNotificationChannel itself

following promotion of DRTVWR-514

This reverts commit a66932a0.

buildConversationViewParticipant() was deparenting view models that belong to session

Looks like viewer is missing some certs in the bundle or doesn't know how to handle web page's certs. For now disabling verification to not block DRTVWR-516. Verification was originally turned on in DRTVWR-516's SL-13927

1. Due to desync participant can be NULL - added NULL checks
2. With large backlog of events, closing and then opening a goup session was causing a crash due to obsolete events - added cleanup for backlog
3. In some cases events were accumulating faster than they were processed - ensured that after certain point event processing scales up with a backlog

Opening already open and recently created experience was crashing viewer due to viewer treating 'edit_experience' as part of floater's key.

This reverts commit b1ab29ee.

This reverts commit 88746478.

following promotion of DRTVWR-532

This reverts commit e61f485a, reversing
changes made to 00c47d07.

This reverts commit 4add069c.

fix by Ansariel (https://vcs.firestormviewer.org/phoenix-firestorm/changeset/dace23b988af90a65ef57b0b9f540fc48d439dc3)

fix by Ansariel (https://vcs.firestormviewer.org/phoenix-firestorm/changeset/5f927b52fdfeebb5db595c7c60c711cee383820b)

following promotion of DRTVWR-519

following promotion of DRTVWR-517