saveSafetyParams saves safety parameters for a group to disk (XML)
 
    This method saves data from a SafetyParamsStruct in a human
    readable XML format on disk.  This allows safety parameters to
    be saved, revisioned, and shared across different APIs.
 
    This format is the preferred way of storing and loading parameters 
    for different demos / applications.  More information on the safety
    parameters XML format can be found at:
    https://github.com/HebiRobotics/hebi-xml/blob/master/SAFETY.md
 
    Examples:
       % Make a new set of safety parameters and save to XML
       safetyParams = SafetyParamsStruct();
       safetyParams.positionMinLimit = [-pi -pi -pi -pi];
       safetyParams.positionMaxLimit = [+pi +pi +pi +pi];
       xmlFile = HebiUtils.saveSafetyParams(safetyParams, 'MySafetyParams');
       display(xmlFile);
 
       % Save the safety parameters that are currently set for a group
       safetyParams = group.getSafetyParams();
       xmlFile = HebiUtils.saveSafetyParams(safetyParams, 'MySafetyParams');
       display(xmlFile);