Verify SearchBound/FlightBound CCW

[miyatakazuya]

Pathing code expects polygons to in CCW order. Want to verify this when mission is uploaded.

• Update POST /mission handler in gcs_routes.cpp
• Should parse the mission.searchBound to check if CCW order is valid
• If not return, 422 (Unprocessable Entity) status code.

Test by:

• Run OBC & GCS, test uploading a mission with correct input AND incorrect input.