Add check-new-user(s) commands for immediately wiping spam users
99% of spammers on our instance come from gmail but there are a few patterns that are detectable.
damspam check-new-user is intended to be invoked immediately after user creation. This allows us to check the user for some known patterns and immediately wipe them.
damspam check-new-users is the more interactive tool to check which users would be caught by the current rules.
cc @karolherbst
Draft because this needs tests so we can't accidentally deploy something that wipes all gmail users.
At the time of filing this, running damspam.py --readonly --verbose check-new-users --created-after="2h ago"
would wipe 12 out of the 22 users, all due to their email in this instance (some with too many periods, some with banned words separated by periods)