Changes to Delete end clients in bulk

the response property code became optional for the status 400

the response property code became optional for the status 500

the response property message became optional for the status 400

the response property message became optional for the status 500

the code response's property type changed from string to integer, and format from no format to int32 for status 400

the code response's property type changed from string to integer, and format from no format to int32 for status 500

removed the optional property details from the response with the 400 status

removed the optional property details from the response with the 500 status