Feature request: admins to have the ability to "close" a thread

[smoya]

Sometimes, threads can blow out or go out of control 🔥 . Slack doesn't have the future for not allowing more people to write in a thread but maybe Candebot could help by adding a new action on message threads where admins can set a thread as closed, so Candebot removes any new message posted in there from that time, adding a ephemeral message (only visible to the user) saying the thread is closed.

For this, we would need a DB to store the state.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[gonzaloserrano]

Optionally avoid new anonymous messages.