Add missing fields to Machine and Interface

[mpontillo]

The hardware_info field returned from the machine read API is not currently represented in python-libmaas. This field should contain information such as the following:

  "hardware_info": {
    "system_vendor": "Canonical",
    "system_product": "ORANGE-BOX",
    "system_family": "C42",
    "system_version": "Unknown",
    "system_sku": "012345678",
    "system_serial": "C42-A",
    "cpu_model": "ARM64",
    "mainboard_vendor": "Canonical",
    "mainboard_product": "ORANGE-BOX",
    "mainboard_serial": "987654321",
    "mainboard_version": "1.05",
    "mainboard_firmware_vendor": "European Megatrends International, LLC.",
    "mainboard_firmware_date": "07/04/2023",
    "mainboard_firmware_version": "1.5",
    "chassis_vendor": "Canonical",
    "chassis_type": "Other",
    "chassis_serial": "654321",
    "chassis_version": "Unknown"
  },

In addition, the product field is missing from the Interface type.