Support for native Tesla integration

[KrzysztofHajdamowicz]

Is your feature request related to a problem? Please describe.
By reading your code, I see that You prefill config_flow with entities if VW integration is used.
It would be great if Tesla integration will be integrated same way.
https://github.com/alandtse/tesla

Describe the solution you'd like
If Tesla integration is configured in Home Assistant instance, fill "ev smart charging" configuration form with entities describing Tesla Vehicle

Describe alternatives you've considered
As for now, I set up manually "ev smart charging" integration