CRM-21134 fix enotices in payment processor code assignment.

CRM-21134 fix enotices in payment processor code assignment.

This is generally a code tidy up to push out the principles we have been implementing (ie.
the idea that the processors define their fields. The code can cause e-notices in extensions as is
because it is prescriptive about fields.

I removed the ANDing in the tpl because actually we are not looking to match numbers like 2
2 is the number we have hard-coded for direct debits (we should be using an option group but that
is another story