Globally refocus after search

[Rohitth007]

We currently can locally refocus back to the index before panel search in the left and right column.
A more useful feature would be to focus back to where it was before search if it was not in the stream/topic/user list.
Eg: If we are in the message view and press q, escaping should bring us back to that message.

[neiljp]

Rereading, the concept appears to be that

• currently going in/out of search in the side panels saves the previous position, eg. see view: Fix focus index before and after Panel Search. #978
• (this was also updated for topic position per stream subsequently)
• upon noticing a search keypress we could also save the previous state, such as if in the central message list (or elsewhere)
• backing out of a search (typically esc) would then restore that state

If we went with this, this could interact with displaying what Esc does, via eg. #1060 (comment)

Discussion was at: https://chat.zulip.org/#narrow/stream/206-zulip-terminal/topic/Globally.20refocus.20after.20search.20.23T1049

To explore the issue, please read that and continue discussion there.