Navigator: add method to set an annotation filter externally

With the help of this any method could force an existing navigator instance to
display a simple annotation filter node. It will create a home none, link it to
an annotation list node and link that in turn to an annotation filter node with
the requested annotation.
Annotation search: add more useful annotation click behavior

If one now clicks on an annotation name in the result list, a new navigator
window opens with a preset annotation filter matching the clicked annotation.
One can still remove the annotation by clicking the small red sign to the right
of every annotation in the result list.