Changes to Send conversation message

added the new system enum value to the message/type response property for the response status 200

added the new optional request property attachments

added the new optional request property senderProfileId

added the non-success response with the status 503

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

added the optional property issues to the response with the 401 status

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

added the optional property issues to the response with the 500 status

added the optional property message/attachments/items/downloadUrl to the response with the 200 status

added the optional property message/attachments/items/s3Key to the response with the 200 status

added the required property message/attachments/items/contentType to the response with the 200 status

added the required property message/attachments/items/filename to the response with the 200 status

added the required property message/attachments/items/size to the response with the 200 status

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

added the optional property retryable to the response with the 401 status

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

added the optional property retryable to the response with the 500 status

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

added the optional property code to the response with the 401 status

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

added the optional property code to the response with the 500 status

the response property success became optional for the status 400

the response property success became optional for the status 401

the response property success became optional for the status 404

the response property success became optional for the status 500

endpoint added