Changes to Create a conversation

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

added the new internal_error enum value to the error/type response property for the response status 401

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

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

added the new permission_error enum value to the error/type response property for the response status 401

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

added the optional property error/provider to the response with the 400 status

added the optional property error/provider to the response with the 401 status

added the optional property error/provider to the response with the 500 status

the items/items request property type changed from array to object

endpoint added