Update the actuator @Enpoint` infrastructure code so that operations
may inject enums that indicate the type of output to produce. A new
`Producible` interface can be implemented by any enum that indicates
the mime-type that an enum value produces.

The new `OperationArgumentResolver` provides a general strategy for
resolving operation arguments with `ProducibleOperationArgumentResolver`
providing support for `Producible` enums. Existing injection support has
been refactored to use the new resolver.

See gh-25738