Asserts

[JonasJurczok]

Faketorio needs a way to assert results. Either we pull in a lib (complicated) or just copy the needed basic asserts (easy)

[terite]

I was able to run luassert in the factorio lua runtime by coping the files and manually requiring some ?/init.lua files.

If something like that is viable, I think it would be the ideal solution because:

• less code to write
• lua devs may already be familiar with it through busted

[JonasJurczok]

QOL functions missing:

• assert element exists
• assert element does not exist