[feature] Auto-detect bad usernames/nicknames

[Laogeodritt]

Automatically validate nicknames and usernames of users against a reference pattern.

Use case: detecting symbol nicknames or otherwise hard-to-read/communication-problem nicknames

DocMonocular's auto-detect bad username functionality - needs to be fixed (syntax errors), documented in the autogeneration format, tested, moved over to ModTools, etc. etc. https://github.com/Worldbuilding/kaztron/blob/9c28f6184abd547806a3b634f4c74f86b6486e4b/kaztron/cog/welcome.py

[Laogeodritt]

• wordfilter-style keyword detection? Could include removal of messages by/mentions of a user

[Laogeodritt]

• Detect bot/spammer links in nicknames (e.g. twitter)