Traccar integration: add "battery charging" attribute

[Ildar_Gabdullin]

Currently the Traccar seems to acquire a “battery charging” bool flag from a mobile device.
It is displayed both in Traccar Web manager & iOS Traccar Manager:

But the HA Traccar integration does not have this attribute:

Please add the “battery charging” attribute to the HA Traccar integration.

[Ildar_Gabdullin]

The “charge” attribute is provided by Traccar & can be added to HA.