Add build-time failure tests for the Categorifier plugin

[zliu41]

We should have tests that ensure that incorrect use of the Categorifier plugin produce appropriate failures at build-time. E.g.,

• converting a type that is missing a necessary instance,
• converting with a hierarchy that doesn't support a necessary operation, or
• converting a term that kitty-cat just plain can't handle.

(Extricated from https://kitty-hawk.atlassian.net/browse/SW-1298)