Fix package tangle in the actuator endpoint package by relocating a
few classes.
The `Producible` and `ProducibleOperationArgumentResolver` classes have
been moved from `endpoint.annotation` to `endpoint` since they aren't
directly tied to annotations.
The `ApiVersion` class has been moved from `endpoint.http` to
`endpoint` since it needs to implement `Producible` and isn't really
tied to HTTP.
Closes gh-25914
e4164d0143