Support multiple local Tesla Energy Gateways (Powerwall/Inverters) using the server for local or cloud access

[Nexarian]

I'm referencing this line: TODO: Add support for multiple Powerwalls

As I have two side-by-side (SxS) Tesla 7.6 kw inverters, this feature is a must for me if I'm going to monitor my system using Powerwall dashboard, especially important is TEDAPI mode and a facility to alternate network routes to interleave data from the two.

This issue is to track development. I intend to tackle this myself.