drivers/apator: decode HCA proprietary payload

[mac22]

Summary

• add a custom decoder for the existing Apator HCA driver
• decode e-itn-30.51 proprietary 15-byte APDUs into Units, RefUnits, TempC, Marker, and Flags
• keep existing APA/APT MVT registrations unchanged
• add a bad-length fallback with byte count, status, and raw hex rows
• add a sanitized regression test using only the APDU payload, without real meter IDs or full captures

Testing

• make -B -C tests check
• make -C tests check
• focused Apator HCA regression
• ufbt