Expose a new 'PUT' endpoint on ServiceServlet to update an existing service.

The implementation should perform the same validations and checks on the given service as is currently done for the create service endpoint (except validating the service does not already exist).

The existing vertex should be deleted and a new one created based on the given yaml.

The identifiying information should be the same in the new and old services (UUID, uniqueID, invariant uuid, name, version)

A service must be in checked out state for the update to be accepted and there shall be no change in state as part of the import

On error, reply with meaningful useful error message and rollback any changes made