A Place of type GeographicAddressReference should optionally allow the sub-address (and sub-unit) to be specified

[fahimsabir-colt]

When specifying a place in a POQ, Quote, or Order, you can specify a fully qualified address (Fielded or Formatted) which goes down to the site level. This works for new service sites at new addresses, but doesn't work where a new service site is requested at an address that already has an identifer (and should be using GeographicAddressReference).

The best way to resolve this would be to include geographicSubAddress as an optional attrubute of GeographicAddressReference. This would look something like this:

    GeographicAddressRef:
      allOf:
        - $ref: '#/components/schemas/GeographicAddressRefOrValue'
        - properties:
            href:
              description: >
                Hyperlink to the referenced place Hyperlink MAY be used by the
                Seller in responses Hyperlink MUST be ignored by the Seller in
                case it is provided by the Buyer in a request
              type: string
            id:
              description: >-
                Identifier of the referenced Geographic Address. This
                identifier is assigned during a successful address validation
                request (Geographic Address Management API)
              type: string
            geographicSubAddress:
              $ref: '#/components/schemas/GeographicSubAddress'
              description:
                Additional fields used to specify an address, as detailed as
                possible.
          required:
            - id
          type: object
      description: >
        A reference to a GeographicAddress resource available through
        Addressing Validation API