This plugins receives packages with type "kdeconnect.battery" and reads the
following fields:
isCharging (boolean): If the battery of the peer device is charging
currentCharge (int): The charge % of the peer device
thresholdEvent (int) [optional when = 0, see below]:
means that a battery threshold event were fired on the remote device:
0 := no event. generally not transmitted.
1 := battery entered in low state
This is an int so in the future we'll be able to subscribe to more events.
(see BatteryPlugin.ThresholdBatteryEvent)
Symmetrically, it sends its own battery information in packages with the same
format. We only look for the 'primary' battery of the system, if one is present.
<TODO>
Support for devices with multiple batteries isn't there yet.
</TODO>
It also sends packages with type kdeconnect.battery and a field "request": true,
to ask the peer device to send a package like the mentioned above, and should
also answer this same kind of packages with its own information.
If the battery is low and discharging, it will notify the user.
