Redact buttons should only be shown if you have privileges to use them

[matrixbot]

Created by @ matthew:matrix.org.

[rubo77]

And If you have moderator rights, they should be easyer accessible somehow. at the moment it is a pain to delete a lot of messages, because you always have to

1. klick
2. move mouse a bit right
3. klick again

maybe #2604 would be a solution

[t3chguy]

fixed by #3925