Add transaction partner code on the invoice template

[vohmar]

Starting from 2024 EIS is mandated to file monthly reporting for balance and payment data. Together with this we need to add transaction partner code to our invoice templates together with registry and VAT numbers

Transaction partner code / tehingupartneri kood: TP 012311

In reality this number is important only to other Estonian orgs that also have transaction partner code. So we have to options here

1. add this nr to invoice template by default and thus display this on every created invoice
2. add this nr only to invoices for orgs that also have such a number ie public sector organizations and private sector organizations established by Estonian Gov. For this we could add a special parameter to the customer/partner profile. So if a registrar has this field filled with their own transaction partner code we will also include our code in the invoices issued to them. We could should make this parameter available in the registrar portal as well so that registrar could manage it themselves.

NB: we have at the moment 1 registrar that falls into this category requiring transaction partner code on our invoices.