Spreadsheet round-trips commonly convert codes like "0115" to the number
115. This pads digit codes back to their official width: 6 for DTMNFR
(freguesia), 4 for DTMN (municipio), 2 for DT (distrito/ilha).
Examples
pt_pad_code(c(115, 1106), "municipio")
#> [1] "0115" "1106"
