Codechange: Let the compile generate the master command table out of templated command traits.

This is using a non-intrusive type-traits like templated system, which
allows compile-time validation that the command table and the command
enum match up.

src/station_cmd.cpp

@@ -56,6 +56,8 @@
 #include "linkgraph/refresh.h"
 #include "widgets/station_widget.h"
 #include "tunnelbridge_map.h"
+#include "station_cmd.h"
+#include "waypoint_cmd.h"
 
 #include "table/strings.h"