TEIIDDES-1610: Fix validation errors on refactoring resource

* If a resource has dependent resources then the latter's external
  references are broken as a consequence of the move (prior to fixing their
  proxy uris). The breaking resets the uris as the resource and discards
  the crucial fragments pointing to the actual eObject uuids. It is
  impossible in EMF to tell exactly where this occurs!!

* Before, moving the resource, this unloads the dependent resources which
  appears to stop the shortening of the proxy uris. As long as the proxy
  uris keep their uuid fragments, the refactoring move works correctly and
  no references are left unresolved when the refactoring has completed.