[REQ][jaxrs-spec] Improved support for using sub-resource locators in jaxrs-spec generators

Is your feature request related to a problem? Please describe.

When using JAX-RS sub-resource locators i currently have to hand code the @Path annotation, which is annoying and error prone.

Describe the solution you'd like

I would like the content of the @Path annotation on the generated api classes / interfaces to be made available as constants, so they can be used in my sub-resource locators.

Additional context

Example sub-resource locator;

`@ApplicationScoped
@Path("my-prefix/{arg1/{arg2}/" + RestResourceRoot.APPLICATION_PATH)
public class SubresourceApiLocator {

@Path(SubresourceApi.PATH)
public SubresourceApi get(@PathParam("arg1") final String arg1, @PathParam("arg2") final String arg2) {
    return new SubresourceImpl(arg1, arg2);
}

}`

Start in the jaxrs-spec generators and inspect how generated API classes and interfaces currently receive their @Path annotations. Add generated constants exposing those paths, then verify that the constants can be used by sub-resource locators like the example; the payload does not name a specific test or file.