mavlink/lib: move open_drone_id helpers to mavlink

I could not extract the open_drone_id helpers to a separate lib because
it would require the mavlink headers while the mavlink library would
also depend on it, so it ended up being a circular dependency.

Instead, I'm now just using the headers from within the mavlink module
as well as from the uavcan driver.

src/drivers/uavcan/remoteid.cpp

@@ -32,7 +32,7 @@
  ****************************************************************************/
 
 #include "remoteid.hpp"
-#include <lib/open_drone_id/open_drone_id_translations.hpp>
+#include <modules/mavlink/open_drone_id_translations.hpp>
 #include <drivers/drv_hrt.h>
 
 using namespace time_literals;