Changes to Transparent MCP proxy endpoint

removed 'propertyNames' constraint from the error/param response property for the status 400

removed 'propertyNames' constraint from the error/param response property for the status 401

removed 'propertyNames' constraint from the error/param response property for the status 403

removed 'propertyNames' constraint from the error/param response property for the status 500

the error/param response's property type changed from object null to string null for status 400

the error/param response's property type changed from object null to string null for status 401

the error/param response's property type changed from object null to string null for status 403

the error/param response's property type changed from object null to string null for status 500

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

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

added the optional property error/params to the response with the 403 status

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

endpoint added