Update ForeignKeyField to new CRUD

This does the necessary work of adopting the DialogObjectForm
, using the queryMixin
& removing the handleUpdate method that's now done by DialogObjectForm
itself.

It also removes pass-through props to DialogObjectForm. This was done
in CRUDBar as well.
But it's a controversal solution, I have to admit.
It might be better served by a suitable mixin.
Anyway look how many lines it removes.

This is up for debate (#918). Let's find a solution that satisfies all
and is suitable for the CRUD.