Improve bank proceeds' autocheck

[vohmar]

By implementing LHV Connect we enabled automatic bank prodees checking to mark unpaid invoices as paid as soon as the funds have arrived in case of bank transfer by the registrar.

For invoice matching it is required that reference nr, invoice nr on description field and invoice amount match in invoice and payment receipt. It turned out that reference nr used by estonian electronic banks is not international banking standard and often foreign registrars do not have this option on transfer.

To solve this issue I propose to drop invoice number verification and limit invoice matching requirements with registrar specific reference number that is looked for in the transfer description (pattern matching) or in reference nr field if such is present, and invoice sum.

PS: Choice to use registrar based reference nr instead of invoice nr is due to plan to implement feature that would create the invoice automatically in case there is no unpaid invoice in matching total sum for that specific registrar (identified by the refnr).

[vohmar]

closed by #1450