Add a "merge multiple responses" admin post selection action

[meglio (Anton)]

I too would need such a button. My use-case is described in details here:

"Join messages" button for admin

I noticed some users put a lot of small messages in a row in the same topic. I suspect different possible reasons: Some don’t understand that there might be multiple “quoted replies” in a single message Others just write messages bit by bit and feel better like this Others put one photo at a time and submit it (maybe after experiencing problems with really slow mobile connection?) Anyway, it would be useful if mods were able to select a few messages, then click the wrench button, and then ch…