Add `pop` method to reflection `List` trait

[alice-i-cecile]

Yeah that's what I was getting at in my other comment. I don't think it's going to be beneficial to add a new trait for each data structure type. That can probably be served somehow via TypeData.

But a pop method at least let's us handle lists, queues, and stacks in a general way.

Originally posted by @MrGVSV in #5792 (comment)

[MrGVSV]

I believe this was handled in #5797