Suggest deactivating user whenever someone is banned for spam

[MadLittleMods]

When we !mjolnir ban someone, the bans only apply to Mjolnir protected rooms. This means that the spammer can still go around and attack other unprotected rooms and rooms on other servers.

After banning, it would be nice if Mjolnir suggested !mjolnir deactivate so we never forget. Deactivating the account stops the spammer from using the server altogether. This could be a 1-minute follow-up question with some quick actions to proceed/ignore or we could do the action automatically as a sane default.

[MadLittleMods]

Another probably better alternative to deactivating an account (which is destructive action) is to use shadow bans and MSC3939 for account locking which can easily be reversed if necessary (also see element-hq/element-meta#1021)

Although deactivation is at least a step forward iteration in any case.