Implement/Support ‘Reply threads’

Currently multiple people replying to single person’s message/holding a discussion off of that single message, clutter entire channels.

This gets messy when people start other topic(s) in the same channel simultaneously + once again have follow up replies/conversation going.

Implementing ‘Reply threads’ will solve this problem.

Reply threads work as follows:

1. Group the replies/conversation concerning a single message under that message, to be expanded/popped open in a side panel, on-demand.

2. Provide easy access to ongoing reply threads(conversations) a particular user is part of, via a ‘live-threads’ meta-channel