Add source_node to cav_msgs/SystemAlert

[msmcconnell]

PR Details

Description

This PR updates the ROS1 version of the SystemAlert message to include the source_node field used in ROS2. This will allow the health_monitor to distinguish between ros1 and ros2 nodes.

Related Issue

Supports https://github.com/usdot-fhwa-stol/carma-platform/issues/1661

Motivation and Context

See issue

How Has This Been Tested?

Black pacifica

Types of changes

• [x] Defect fix (non-breaking change that fixes an issue)
• [ ] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (fix or feature that cause existing functionality to change)

Checklist:

• [ ] I have added any new packages to the sonar-scanner.properties file
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document. CARMA Contributing Guide
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.