Improving Tag and Tags annotations

[navidsh]

@Tag and @Tags annotations can be defined in one JAX-RS resources class and used in other classes. In the open source Swagger annotation definition, it is confusing how to refer to tags in different annotations.

Here is the proposal:

• Adding the ref @Tag:

org.eclipse.microprofile.openapi.annotations.tags.Tag:
public @interface Tag {
    ...
    String ref() default "";
}

If ref field is defined in a @Tag, there is no need to define the name field.

• Adding the ref s@Tags for easy referencing multiple tags:

org.eclipse.microprofile.openapi.annotations.tags.Tags:
public @interface Tags {
    ...
    String[] refs() default {};
}

[navidsh]

I am working on this issue.

[arthurdm]

Solved via merge #49