Add more customize features Energy flow

[daimonkor]

Hello, please add support the current features:

1. override_state for home and set custom sensor
2. add support more than 1 source to charge batteries. I have one battery, so I have one source for discharge, but charge sources are grid and solar
   The main problem is self usage of invertor. Off course, the information with full solar production is interesting, but I can not show one, because "home" usage will invalid.