typing, mostly in AutoWorld.py

[beauxq]

typing, mostly in AutoWorld.py
includes a bug fix (that was found by static type checking)
in get_filler_item_name

[Berserker66]

this contains a bit of a stylistic choice of including -> None, which personally I find to be more clutter than useful. Do we want to start adding that everywhere?

[beauxq]

mypy, which is one of the most popular static type checkers, requires -> None in order for the function definition to be typed.

It is incapable of giving the same quality of analysis without it. So it is not just a stylistic choice.

[beauxq]

pyright also, with its most strict settings, will not emit that a return type annotation is missing when something besides None is returned.

[beauxq]

I agree that it adds a lot of clutter. So I made this feature request on mypy.

python/mypy#12695

But I don't expect it will be implemented any time soon, or maybe ever. I might anticipate the response "Explicit is better than implicit."