FEAT: Get informations about the UPS battery in the front-end

[RoiArthurB]

Feature Request

Checklist

• Do you want to make a PR for this?
• Have you discussed this feature with the team?
• Is there a related issue or feature request?
• Do you have any mockups or designs for this feature?

Description

Since the last PR ( #135 ) been merged, it's now possible to monitor and get information about the UPS in the M2L2.

Therefore it would be great to be able to actually monitor them and give useful feedback to users if the battery is very low or other related stuff.

Why is this needed?

Additional Notes

Answer the point Monitor when it's about to shutdown (TODO) from the PR