Add AnnotationConfiguration component to allow consistent retrieval of the Annotation Application's settings

Currently, the Annotation Application manually retrieves the configuration directly accessing the configuration object from the configuration page.

A more elegant and reusable way is to provide an AnnotationConfiguration component that internally uses a ConfigurationSource that fetches the configuration from the object in the configuration page. It should also always retrieve the configuration of the AnnotationApplication from the current wiki (as defined by the context).