Moving the code to separate files. Functionally should be no
differences.

This is a more elegant way of implementing a month ahead version of the
percent goals. To use it add the `previous` flag to the percent goal, ex
`#template 10% of previous Paycheck`.

Fixes #1409. This makes the template processing not include previously
budgeted funds in the return value.

Co-authored-by: biohzrddd <10577752+biohzrddd@users.noreply.github.com>

The change isn’t so new anymore so I’ve updated the comment to recognize
that.

Co-authored-by: biohzrddd <10577752+biohzrddd@users.noreply.github.com>

Renaming all occurrences of Nordigen to GoCardless

fix #1301

After the change, upper components will not detect the press enter event
before the datepicker is closed.

I _think_ this no longer applies?