ibootbar: publish current and voltage to a feed and session.data

[ykyohei]

Description

Add current and voltage to a feed and session.data of ibootbar agent.

Motivation and Context

Even though the ibootbar outlet is on, a device on the ibootbar can fail and stop. To detect the failure of air compressor which do not have its agent, we would like to monitor the current draw of ibootbar to detect failure of device.

Voltage can only be monitored by IBOOTPDU.

How Has This Been Tested?

Tested at daq-dev for both IBOOTBAR and IBOOTPDU.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.