"planet" event filter for entity-related events

[MeteorSwarm]

Some modded planets use scripts to influence the behavior of entities when placed. Some planets, such as Maraxsis, have far-reaching effects on every entity in the game when placed. When too many mods use unscoped events when entities are built like Maraxsis does, this creates a performance problem when entities are placed. This issue could be addressed with a "planet" event filter, allowing events to only fire when the relevant entity is on a particular planet.

[protocol_1903]

If planet is too specific, maybe surfaceID. But I feel that planet is more likely to be added.

[robot256]

+1. SurfaceID would be the right approach. Lots of mods have special surfaces not attached to a planet, or multiple surfaces that represent the same planet.