Allow @ResponseBody on the type level

This change enables having @ResponseBody on the type-level in which
case it inherited and does not need to be added on the method level.

For added convenience, there is also a new @RestController annotation,
a meta-annotation in turn annotated with @Controller and @ResponseBody.
Classes with the new annotation do not need to have @ResponseBody
declared on the method level as it is inherited.

Issue: SPR-10814