Remove 'new' OFX parser as it is too buggy (#1111)

Draft because it is untested, maybe tonight I will test it! Just wanted
to get some code out cause i had a spare 5 minutes.

The new parser isn't immediately good enough to replace the old parser,
and I sadly lost the time to contribute more! Sorry! If someone else
wants to take maintenance burden of this code, we can not merge this.
Otherwise, it should go the way of the Dodo it seems.

Thanks!

Closes #1044