[haroldadmin]

Cleans up the moderation crate's API.

• Separate the concepts of labels and actions, even though they appear similar on the surface
• Introduce the concept of moderation "subjects" to supply typed information to the moderation crate
• Use generated types from Typesafe's OpenAPI spec, instead of hand written structs

It does away with the nonsense abstractions and APIs around fast path checks, and untyped JSON values being passed around.