TRACKING: Topic muting improvements

[preetmishra]

• Do not show muted topics in stream narrow (and stream unread count)
• Support event handling for muted topics (proposed by @neiljp)
• Handle setting unread count for muted topics
• Support topic muting/unmuting (see also [WIP] - Mute topics from within ZT #467)
• Update these topics when topics are re-named [since they're text, not an id] (proposed by @neiljp)

[kaustubh-nair]

@preetmishra I renamed #574 because the PR linked to that issue isn't supposed to handle topic unread counts. It only fixes the bug caused by improper _found_newest handling.

[neiljp]

Also updating of these topics when topics are re-named (since they're text, not an id)

[Laanan]

Hi folks, piggybacking on this issue:

• allow moving topics to new streams (private to private, private to public, and public to public).

Also, how can I help? I merely dabble in programming, but is there another way I can contribute to the project?

[neiljp]

@Laanan Filing issues is a great start, and if you want more freeform discussion then you're welcome to join #zulip-terminal on chat.zulip.org :) Of course you're welcome to contribute in other ways, like with code - there may be some 'good first issue' issues remaining, or just take a dive in the code and see how it works, or figure out how to solve something that's bugging you!