fix: structured codes use separate street / building number

As per:

https://www.paymentstandards.ch/dam/downloads/ig-qr-bill-en.pdf
Specification: Swiss Implementation Guidelines QR-bill
(version 2.1 from 30 September 2019 at the time of writing)

Page 31, Technical specifications, Use of address information.

cmd/qrbill-api/api.go

@@ -48,8 +48,8 @@ func qrchFromRequest(r *http.Request) *qrbill.QRCH {
 			Cdtr: qrbill.Address{
 				AdrTp:            qrbill.AddressType(ifEmpty(r.Form, "craddrtype", string(qrbill.AddressTypeStructured))),
 				Name:             ifEmpty(r.Form, "crname", "Legalize it!"),
-				StrtNmOrAdrLine1: ifEmpty(r.Form, "craddr1", "Quellenstrasse 25"),
-				BldgNbOrAdrLine2: ifEmpty(r.Form, "craddr2", ""),
+				StrtNmOrAdrLine1: ifEmpty(r.Form, "craddr1", "Quellenstrasse"),
+				BldgNbOrAdrLine2: ifEmpty(r.Form, "craddr2", "25"),
 				PstCd:            ifEmpty(r.Form, "crpost", "8005"),
 				TwnNm:            ifEmpty(r.Form, "crcity", "Zürich"),
 				Ctry:             ifEmpty(r.Form, "crcountry", "CH"),