Utils: Fix mistake made with KeyedDefaultDict from #1933 that broke tracker functionality.

[ThePhar]

What is this fixing or adding?

During #1933, I defined a custom __init__ for Utils.KeyedDefaultDict to make PyCharm happy when creating a new dict, but forgot to add a *args param, which was only utilized in the tracker code, so I missed in testing. This adds it and fixes the 500 server error that gets displayed on multitracker.

How was this tested?

Ran WebHost before and after.

If this makes graphical changes, please attach screenshots.

Before:

After:

:P

[beauxq]

If what you have solves the immediate problem, it might be best to merge it and work on the typing later, just to get things fixed.

But if you want to get correct typing, you can try this. I ran unit tests with it and looked at references, but you might know better than me how to test it well.

KT = typing.TypeVar("KT")
VT = typing.TypeVar("VT")


class KeyedDefaultDict(Dict[KT, VT]):
    """something like defaultdict that uses the missing key as argument to default_factory"""
    default_factory: typing.Callable[[KT], VT]

    def __init__(self,
                 default_factory: typing.Callable[[KT], VT],
                 mapping: typing.Union[typing.Mapping[KT, VT], typing.Iterable[typing.Tuple[KT, VT]], None] = None,
                 **kwargs: VT) -> None:
        self.default_factory = default_factory
        if mapping is not None:
            super().__init__(mapping, **kwargs)
        else:
            super().__init__(**kwargs)

    def __missing__(self, key: KT) -> VT:
        self[key] = value = self.default_factory(key)
        return value

I don't see a good reason to be inheriting from defaultdict
The typing of default_factory is definitely incompatible with it.

I also don't see a good reason to allow not giving a default_factory to __init__
(If you don't have a default_factory why would you use this class?)

[ThePhar]

For now, I'm going to merge this to fix the bug currently affecting the tracker. We can revisit improving the typing in another PR.