expose upgrade direction in LuaEntity

[Jaren Taq]

Hello,

since the new upgrade system can change the direction of an entity, it would be nice if this information can be exposed by the LuaEntity API. Proposal:

• extend order_upgrade argument table with direction
• add a new function get_upgrade_direction()

Additionally, the event table of on_marked_for_upgrade could be extended by the new direction.

With this information mods like Nanobots, Construction Drones or Bluebuild could also handle this case.

Thanks, Jaren

[Rseding91]

Ok, I added a function to read it, and set it during order_upgrade + in the event.