Add powerboard measurements to Solo12 sensor data

[luator]

Description

open-dynamic-robot-initiative/master-board#98 Adds support for a separate power board that provides measurements of current, voltage and energy.
This PR adds the corresponding values to the sensor data of Solo12.

How I Tested

Running a dynamic_graph_head example and print the powerboard values there.

Do not merge before

• Partial support of the new Power-Board hardware master-board#98
  (Note: It will still work without power board as well (the values will simply be zero if non is connected), but I am not sure if the firmware needs to be updated nonetheless to be compatible with SDK changes).
• Corresponding PR on odri_control_interface (PR not yet created).

I fulfilled the following requirements

• All new code is formatted according to our style guide (for C++ run clang-format, for Python, run flake8 and fix all warnings).
• All new functions/classes are documented and existing documentation is updated according to changes.
• No commented code from testing/debugging is kept (unless there is a good reason to keep it).

[jviereck]

Thanks for adding this @luator.

I suggest we merge these changes once the power board change lands.