NMOC: MeasureSubType subType

Values from NMOC:

• "GROUND_DELAY"
• "TAKE_OFF_NOT_BEFORE"
• "TAKE_OFF_NOT_AFTER"
• "MINIMUM_DEPARTURE_INTERVAL"
• "MILES_MINUTES_IN_TRAIL"
• "GROUND_LEVEL_CAP"
• "AIRBORNE_LEVEL_CAP"
• "GROUND_HORIZONTAL_REROUTING"
• "AIRBORNE_HORIZONTAL_REROUTING"
• "TERMINAL_PROCEDURE_CHANGE"
• "OTHER_KIND_OF_STAM_MEASURE"