Exposing current power consumption as a custom characteristic for plugs that support it
### Current Situation

I am trying to use a KP115 plug to monitor how much electricity our washer is taking and run an automation that tells us that it is done once it hits a certain threshold. However, I don't have the ability to do this, I just have to rely on the in use switch, which I don't think will be accurate, I haven't tried it. if possible, it would be cool if the current energy consumption would be added as a custom characteristic to devices that support energy monitoring. 

### Proposed Change

The plug-in should pole the plugs and other devices, asking them how much energy there connected devices are drawing. Next, the plug-in should take that information and expose it as a custom characteristic to Apple HomeKit, which could be seen by third-party HomeKit apps like Eve for HomeKit as a custom characteristic available as a trigger in automations.