Allow any iterable for IN operator

[Lucidiot]

The in operator in queries only allows lists or tuples, while all it requires is any kind of iterable, like dicts, sets, frozensets, or even Django's QuerySets:

SomeNode.nodes.filter(
    some_property__in=SomeModel.objects.values_list('some_field', flat=True)
)

Currently, to get this to work, the Django QuerySet must be wrapped in list(), an unnecessary addition. One might use collections.abc.Iterable with isinstance to check for a valid iterable.

[aanastasiou]

@Lucidiot Thanks for bringing this to our attention, sounds good.