Arviz: Lookup not found objects in armarx objects

If an object file could not be found, e.g. when drawn by WorkingMemoryToArViz from another computer, lookup the object name in local ArmarXObjects and use that for visualization.

Occurs when running the robot. WorkingMemoryToArViz draws the ROBDEKON boxes with path /home/armar-user/.armarx/mongo/.cache/files/dirty-box.xml, which cannot be found by the ArViz visualizer locally (e.g. on my user account). In this case, by looking up the object name ("dirty-box") in ArmarXObjects, the object can still be visualized. Lookup took about 0.7 and 30 ms for the two boxes in my case. As loaded objects are cached, this has to be done only once.