PIX QR codes are now generated in the official BR Code format

PIX QR codes used to be written in a format of our own. They are now generated in the official BR Code (EMV) format defined by the Banco Central do Brasil, the one Brazilian banking apps expect: the PIX key, recipient name, city, amount and transaction id go into the standard's fields and the code ends with a checksum (CRC).

PIX codes created earlier were written in the old format; the edit page still reads them.