This adds support for enabling the charge limits via UPower for Desktop's/DE's. The thresholds are not configurable via a configuration file but via hwdb so vendors can override them if desired based on a DMI string. UPower will save the configured state (enabled/disabled) in it's state directory so the charge limits are re-applied on boot if the firmware doesn't "save" charge thresholds.
This notably only supports devices with a start and end charge control threshold. Sadly some laptops LG, Asus do not (yet?) support setting both thresholds.
Something which is likely needed for a follow up is a way to distinguish the battery icon in GNOME for when a battery has limits applied.