Allow AI to form formable civilizations

[Beter Griffin 327]

As of now, AI will never form a formable civilization regardless of how much gold it has. it doesn't make sense for, say, Seville to conquer all of Iberia and not form it, even centuries after the fact.

AIs should be able to form a civilization if they meet the requirements and are in a financially comfortable position (a player would probably not spend all of their money on forming a civ if they have 101 gold with a monthly balance of -6 (unless forming said civ is their endgoal)).

[lavaice 1]

this is a good idea

[Beter Griffin 327]

As an addendum, certain silly nations such as the pizza empire and evil scotland probably shouldn't be formed by the AI. There should be a setting in the formable nations editor on whether the AI can form it or not, something like this

[Bargor 48]

@Łukasz Jakowski it needs to be added!