Single pixel scans

This merge request adds start_row and stop_row parameters to all scans. This enables ROI scans down to single pixel scans if needed. See #71 (closed) Further changes:

• Adding a timeout parameter to RD53A.get_chip_status()
• Change loglevel for RD53A.enable_userk_filter() and RD53A.enable_monitor_data() to debug
• Renaming mask_steps parameter to mask_step
• Cleanup and documentation for all scans