Update OVM to `mesh_copying` and copy mesh instead of raw pointer.
Fixes OpenFlipper-Free#143 (closed). Warning: references non-master commit in OVM, cf OpenVolumeMesh/OpenVolumeMesh!24 (closed)
Corresponding OF CI: https://www.graphics.rwth-aachen.de:9000/OpenFlipper-Free/OpenFlipper-Free/pipelines/6160