Changes to List Postcards

added the optional property data/items/from/allOf[#/components/schemas/Contact]/secret to the response with the 200 status

added the optional property data/items/to/allOf[#/components/schemas/Contact]/secret to the response with the 200 status

added PostcardPremiumPaperID to the data/items/paper response property allOf list for the response status 200

removed PremiumPaperID from the data/items/paper response property allOf list for the response status 200

the paper response's property default value standard was removed for the status 200

added the new internal_server_error enum value to the error/type response property for the response status 500

added the new rate_limit_exceeded_error enum value to the error/type response property for the response status 429

added the new validation_error enum value to the error/type response property for the response status 400

added subschema #1 subschema #2 to the response body anyOf list for the response status 401

removed subschema #1 subschema #2 from the response body anyOf list for the response status 401

added the optional property data/items/paper to the response with the 200 status