Draft: scanner: Aliases of gpointer are pointers

If we have a type alias defined as:

typedef gpointer FooPointer

and we use it inside our API like:

Bar* foo_pointer_get_bar (FooPointer self)

then we want foo_pointer_get_bar to be detected as a method of FooPointer, instead of a global function that takes a FooPointer as its only argument.

This requires checking if the first argument is a pointer type or an alias to gpointer.