Pull Request From GitHub: Only one BIC per bank account (BT-86) (#2)

https://github.com/itplr-kosit/xrechnung-visualization/pull/2

In the section "Überweisung" (BG17) all BICs have been concatenated with a semicolon and were written into all BT-86s. In our opinion, that makes no sense if one uses multiple bank accounts at different banks. Is there a reason for using distinct-values()? Before: Kontoinhaber: Bank 1 IBAN: DE11 1111 1111 1111 1111 11 BIC: DEMO1111XXX;DEMO2222XXX;DEMO3333XXX Kontoinhaber: Bank 2 IBAN: DE22 2222 2222 2222 2222 22 BIC: DEMO1111XXX;DEMO2222XXX;DEMO3333XXX Kontoinhaber: Bank 3 IBAN: DE33 3333 3333 3333 3333 33 BIC: DEMO1111XXX;DEMO2222XXX;DEMO3333XXX