Add battery info to polychromatic-cli

[yoshida-ryuhei]

New feature

• print information about battery by polychromatic-cli

Description

• change Backend so that the data is transferred to polcychomatic-cli
• print information about battery if it exists at polychromatic-cli

Motivation

I want to get the battery level by polychromatic-cli (not just GUI).

I don't understand the side effects and I haven't added any tests, so I'd like to know about that.

[lah7]

Hi. This is awkward because I've been doing some refactoring across the project, so your changes will introduce a conflict. New WIP code is in the backend_refactor branch, and I have a few features to restore and fully test before it's ready to merge into master. I've had a short break working on the project.

One of the things I'm intending to do is create a battery class, so that the % can be exposed in the CLI and tray applet. I'm a dozen TODO's away, but I can work this into the new code when things are in a good state. ⚖️

[yoshida-ryuhei]

Thank you for letting me know about the ongoing refactoring.
I am really looking forward to the refactoring going well, and I am going to wait for the new feature.

[lah7]

Thanks for your patience, and sorry for taking so long.

The proposed feature has been re-implemented under the newer codebase: f8f51a6e1c80b30f6b45a24d4e4edf709ca0d239