If a participant is a JIRA User send them a JIRA notification instead of a SD notification

If a JIRA user is added to an issue as a participant then they should be sent notifications via JIRA instead of Service Desk. The main benefit for this would be that the participant would be sent to the JIRA Issue instead of the Customer Portal, which has less detail and functionality.

At present if you configure the JIRA Notification Scheme to send participants emails it is trumped by the SD Notification System and no no JIRA notification is sent.