UBX-RXM-COR: Differential correction input status
UBX-RXM-RTCM: RTCM input status
These two messages give visibility into the RTCM input status. This would be very useful during debugging or checking whether RTK is working correctly. The proposal is to enable these 2 messages on the module, add logic to parse these messages in the driver, and then publish the important status information to a uORB topic.