Promote/demote owners follow-up

[Antreesy]

UI-wise I see two things:

• It might not be clear from the user perspective what the difference between owner and moderator is.
• Demoting myself has no safety net, press the button and the permission is gone.
• See additional comments in the original PR review

Originally posted by @SystemKeeper in #18924 (review)

[nickvergessen]

It might not be clear from the user perspective what the difference between owner and moderator is.

I wonder where we should add this information?

Demoting myself has no safety net, press the button and the permission is gone.

Makes sense to have a small confirm dialog I guess

[Antreesy]

• Expose owners/moderators in the chat: feat(moderators): Show moderator icons in chat #18925