Summary:
During the import of an OFX investment transaction don't use the memo field as payee in case the payee information is not present. Use the PAYEEID or NAME field in that order only. In other cases leave the payee empty.

Test Plan:
Compile
Run 'make test'
Import OFX download statement for investment account.
Check that payee field remains empty for newly imported transactions.

Reviewers: ostroffjh

Reviewed By: ostroffjh

Differential Revision: https://phabricator.kde.org/D9561