Offer syslog service for system notifications from Controller and Agents

Current Situation

• Output to JOC Cockpit log files at error and warning log levels is considered when creating notifications that become available with the JOC Cockpit's Monitor->System Notifications view.

Desired Behavior

• Notifications should be added to JOC Cockpit from log output created at error and warning log levels with Controller and Agents.
•  Implementation
  • The JOC Cockpit is added a Syslog Service. The service is offered for clustering.
  • Controller and Agents make use of Log4j that can be configured to send log output to a syslog server. The related Log4j configuration is added from JS-2154.
  • The JOC Cockpit syslog server accepts messages from Controller and Agents and creates related notifications for errors and warnings.
•  Operation
  • The Controller and Agents will ship with updated log4j2.xml configuration files that include the Syslog Appender. Users have to activate the Syslog Appender from their log4j2.xml configuration file.
  • The JOC Cockpit syslog service is not active by default. Users can configure the service to be started on start-up of JOC Cockpit.