Changes to Build transaction data for creating a SelfMint drop item

added the new optional request property animation_url

the request property description became nullable

the request property external_url became nullable

the request property traits became nullable

added the media type */* for the response with the status 403

added the non-success response with the status 422

added the optional property code to the response with the 400 status

added the optional property code to the response with the 404 status

added the optional property code to the response with the 409 status

added the required property from to the response with the 200 status

added the required property token_id to the response with the 200 status