C2MS12 — C2MS Database Query (DBQUERY) messages

Add the DBQUERY messages that were defined by NASA to the formal specification.

These messages are listed as being part of the OMG specification here:
https://software.nasa.gov/software/GSC-18536-1

"A Graphics User Interface (GUI) based desktop viewer for XML Telemetry and Command Exchange (XTCE) files which allows some editing of the various XTCE properties of that open file, and then allows saving the updated information back to file. It includes a Goddard Mission Services Evolution Center (GMSEC) GMSEC Search XTCE (GSX) connector to support some GMSEC/ (Command and Control Message Specification) C2MS Database Query (DBQUERY) messages to search for some XTCE information which is then sent over GMSEC bus to the initiator of the search request."

NOTE: C2MS12-2 is being closed as a DUP of this message, so the intent of that issue needs to be addressed in the resolution of this one.