AC

• REST handlers use the new validation mechanism (based on get(Body)ParamSettings) to validate the request body (see T361995).

QA notes

The following endpoint should continue to work normally:

• Enable registration
• Update registration
• Cancel registration (as participant)
• Delete registration
• Email users
• Register for event
• Remove participants
• Set organizers

I.e., no new failures, and parameters are still validated as expected (with particular attention to non-scalar parameters, things such as arrays, usernames, page titles). There is no need to test the actual actions performed by these handlers, or more generally the success states.