Added C interface for TypedListType, GetItem, insert, append and extend

There are surely a lot of bad practises inside my code. I'm all ears for any improvement.

I'm also still wondering how to implement the remove op in c as there isn't any remove function in python list c api. I was thinking about iterating through the whole list, comparing item one by one and once the item to remove is found, shifting all left members of the list by one to the left. But that seems very inelegant.