Implement remote computation #71

To enable remote computation we need to:

• select remote file
• download it
• start a session on the downloaded files
• Save pointcloud and DVC run configuration to file and transfer it to the remote
• Start computation on remote
• Retrieve the results

The first 2 items are implemented in https://github.com/paskino/CIL-work/blob/master/RemoteViewer/TwoLinkedViewersCentralWidgetCompare.py

Last item is done for SLURM remotes in https://github.com/paskino/brem/blob/main/examples/run_dvc_gui.py