Make InvitedPendingFactory moderator an actual moderator

[nlhkabu]

Currently the FK to moderator is only a standard UserFactory: https://github.com/nlhkabu/connect/blob/master/connect/accounts/factories.py#L87

We should really be using a ModeratorFactory here - but I have not been able to get this to work

┆Issue is synchronized with this Asana task