[WIP] Handle typing events from multiple users in a PM narrow

[Subhasish-Behera]

What does this PR do?

Fixes #992

Tested?

• [X] Manually
• [X] Existing tests (adapted, if necessary)
• [X] New tests added (for any new behavior)
• [X] Passed linting & tests (each commit)

Commit flow

Notes & Questions

Basically now the controller.active_conversation_info is a set which adds a sender if the event is "start" and removes if the event is "stop". Reasons for change :-

1. There seems to be no requirement for Dict as It had only one key -"sender"
2. in dict , discarding/removing by element name is not possible (but possible in set)

Interactions

Visual changes

[zulipbot]

Hello @Subhasish-Behera, it seems like you have referenced #992 in your pull request description, but you have not referenced them in your commit message description(s). Referencing an issue in a commit message automatically closes the corresponding issue when the commit is merged, which makes the issue tracker easier to manage.

Please run git commit --amend in your command line client to amend your commit message description with Fixes #992..

An example of a correctly-formatted commit:

commit fabd5e450374c8dde65ec35f02140383940fe146
Author: zulipbot
Date:   Sat Mar 18 13:42:40 2017 -0700

    pull requests: Check PR commits reference when issue is referenced.

    Fixes #51.

To learn how to write a great commit message, please refer to our guide.

[Subhasish-Behera]

Thanks, for your review and time @mounilKshah. Yep, I haven't committed the new tests. (currently working on adjusting the tests after the index by user_id refactor as well as the new test.Should be complete soon)

[Subhasish-Behera]

@zulipbot add "PR needs review"

[zulipbot]

Heads up @Subhasish-Behera, we just merged some commits that conflict with the changes you made in this pull request! You can review this repository's recent commits to see where the conflicts occur. Please rebase your feature branch against the upstream/main branch and resolve your pull request's merge conflicts accordingly.