Move test documents to python folder.
Delete remaining java helper class "TestDocument" and parent folder.

Change-Id: I76ba4e82e96b39df207c337fc1f17052b750774d
Reviewed-on: https://gerrit.libreoffice.org/46188Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>