Prior to this commit, ApiVersion was treated as a mandatory parameter in
CachingOperationInvokerAdvisor and thus prevented the
CachingOperationInvoker to kick in. By skipping ApiVersion in the same
way we're skipping SecurityContext we can avoid this.

In order to not return the same cached response, this commit also
changes the cache handling in CachingOperationInvoker to account for
different ApiVersions being passed.

See gh-18961