Add more verbose logging on syncread failures

[lukeschmitt-tr]

This PR does the following:

• Makes read failures more descriptive
• Adds an additional check where, if any read fails, check what motors we are failing to read from.
• Allows users to define joint state publisher behavior on read failures - opting to use the values provided by dxl_wb (-pi), or using NaN values; the former being the default.

This change will make it easier to diagnose connection problems between motors and better help to detect faulty motors.

Brings in the feature from the ROS 1 SDK added in Interbotix/interbotix_ros_core#44 and Interbotix/interbotix_ros_core#46