This is a follwup to the pre Foxy Message API review

• Comment: Consider replacing NavSatFix with gps_common/GPSFix or add some of the fields from GPSFix (the orientations specifically).
  This better supports dual antenna gps setups where an accurate heading can be provided and synced with the position fix.
• Suggested Action:
  Consider a extending the message with an optional orientation. Or consider a new extended message with orientation added. This message is specifically generic to all GNSS systems versus the GPS one has GPS specific data so is not suitable to be replaced.