Blocking a user adds a note to the account
Problem to solve
Currently, if a user is blocked, the only record of when and how this happened is in the audit logs. It's often useful to have this information directly at hand rather than having to search for it.
Proposal
When an admin blocks a user via the web interface, the controller prepends a message to that user's user notes. Since user notes are visible on a user's admin page, it will be immediately available to anyone looking for it.
Proposed Format
YYYY-MM-DD Blocked by ADMIN
The date is to dismbiguate this block entry from any others, and ADMIN
will be replaced by the login name of the admin who performed the block. A newline will follow to separate it from other notes (if any).