Support struct values in Grid Product

[dplumb94]

Currently Grid Product does not validate struct values based on the product schema. It also does not appear that struct values are being communicated via state delta export to the grid database:

]
    {
        "product_id": "013600000929",
        "product_address": "621dee0201000000000000000000000000000000000000000000000001360000092900",
        "product_namespace": "GS1",
        "owner": "crgl",
        "properties": [
            {
                "name": "width",
                "data_type": "Struct",
                "service_id": "AMOeI-sxKkY::gsAA",
                "bytes_value": [],
                "boolean_value": false,
                "number_value": 0,
                "string_value": "",
                "enum_value": 0,
                "struct_values": [],
                "lat_long_value": {
                    "latitude": 0,
                    "longitude": 0
                }
            }
        ],
        "service_id": "AMOeI-sxKkY::gsAA"
    }
]