Method for locating JAXB XmlAccessType annotation value
for given annotated entity, if it has one, or inherits one from
its ancestors (in JAXB sense, package etc).
Enumeration that defines how we use JAXB Annotations: either
as "primary" annotations (before any other already configured
introspector -- most likely default JacksonAnnotationIntrospector) or
as "secondary" annotations (after any other already configured
introspector(s)).