Save "reporter" and "message" alongside banned users list in moderator instance

[suddenwhipvapor]

Following a case recently where one user couldn't send messages, I was directed at the possibility that the use was banned, and in fact he was in my banned list.
It was done a while ago and I have no memory of the reason, but most probably it was someone with 0 reputation who posted below market offers and was hence reported by one of the mediators.
Having the feature above could have helped in identifying the issue.