Add option to not have to confirm redactions

[benparsons]

Is your suggestion related to a problem? Please describe.
Needing to redact several messages, it's a unneeded extra click for each redaction

Describe the solution you'd like
A setting to not show the confirmation screen.

Describe alternatives you've considered
A per-room setting. I don't think this is needed.

[SimonBrandner]

This would definitely be a great feature, but I feel like #7660 or #3689 would be a better solution for the specific problem

[t3chguy]

I think this is much better served by element-hq/element-meta#920
@benparsons can you confirm if that'd satisfy your usecase?
You would select many and confirm once

[benparsons]

I would prefer not to have to confirm anything, but it would especically help in the case of multiple redactions. I'm not super-attached to this request though.