runtime access to spawner capture mechanics

[SWeini]

I'd like to have access to these properties in runtime stage:
https://lua-api.factorio.com/latest/typ ... get_filter
https://lua-api.factorio.com/latest/pro ... ner_entity

This is needed to calculate availability of items. Just because an item can be produced by an unlocked recipe doesn't mean you can make it. You need access to the whole chain leading to all ingredients and crafting machines and surface conditions and whatnot. Capturing a spawner might be part of that chain of dependencies. Right now I have all the data up to promethium science pack, which needs biter eggs, which needs a spawner to be captured. I'd rather not rely on hardcoding the space-age way of things and instead read this dynamically.

[Rseding91]

Added for the next release.