message-editing: Limit who can "resolve" a topic to those who can post.

[anurastogiji]

Issue #21281

We add a check for people who can send message in the stream and only
those user can resolve the topic of message sent in the stream.

Zoe is normal user and the "resolve" option is not visible to the user since only admin can post in the stream.

[zulipbot]

Hello @zulip/server-message-view, @zulip/server-streams members, this pull request was labeled with the "area: message-editing", "area: stream settings" labels, so you may want to check it out!

[anurastogiji]

@alexmv ,does this implementation look good?

[andersk]

This restriction needs to be enforced on the backend, not just the frontend.

[alexmv]

Doing this limiting on the frontend is a good first step, especially for user experience, but as @andersk points out, we also need to enforce this in the backend.

For the frontend change, it looks like this copies a bunch of code from validate_stream_message_post_policy. We should abstract that out into a common function rather than duplicate it.

[asah]

Also, please add unit test(s):
https://zulip.readthedocs.io/en/latest/testing/testing-with-django.html

[zulipbot]

Heads up @anurastogiji, 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.