[FEATURE]: Integrate ROS diagnostics for hardware diagnostics

[evan-palmer]

Is your feature request related to a problem? Please describe

The Reach Alpha manipulator publishes diagnostic information regrading any hardware errors. It would be useful to utilize these error messages in conjunction with the ROS diagnostics framework to better support evaluation of hardware issues and to enable usage of well-supported diagnostics tools.

Describe the solution you'd like

Construct a callback function to receive diagnostics packets from the Reach Alpha manipulator and republish those using a message from diagnostics_msgs to the /diagnostics topic.

Describe alternatives you've considered

Alternatively, this data could be manually logged and recorded, but this could make it more difficult to integrate external diagnostics tools.

Implementation Ideas

The Reach Alpha manipulator publishes diagnostics information at a rate of 1 Hz using the 0x66 packet ID. A callback method should be implemented to subscribe to messages using the diagnostics packet ID and publish a DiagnosticStatus ROS message from diagnostics_msgs. Furthermore diagnostics aggregators should integrated to collect diagnostics data.

Additional context

An example has been implemented for ROS2 Humble and can be accessed here