[REF] Grant cleanup

[REF] Grant cleanup

This does a couple of things to cleanup the Grant BAO -
1) moves money handling back to the form layer
2) removes unnecessary date handling - the format that comes from the form layer
is now supported by the BAO.

I was looking to work on another but but then figured I needed a v4 api before
writing the tests and then realised we shouldn't do a v4 api before getting
rid of the legacy money handling.

It does occur to me it might make more sense to start moving to an
extension before doing any of the other steps