Add command to allow/disallow charging from the grid and exporting energy to the grid.

[jasonacox]

Add a command line (see CLI options) to pypowerwall to allow user to set grid charging and exporting.

Using FleetAPI: https://developer.tesla.com/docs/fleet-api/endpoints/energy#grid-import-export

API: POST /api/1/energy_sites/{energy_site_id}/grid_import_export

• energy_site_id - ID field of an energy site from /api/1/products endpoint.
• customer_preferred_export_rule - The desired behavior for grid exporting. The available options are battery_ok, pv_only, and never.
• disallow_charge_from_grid_with_solar_installed - The desired behavior towards importing from the grid. Charging from the grid is disabled when set to true and enabled when set to false.

Proposed addition to CLI:

python3 -m pypowerwall set -gridcharging VALUE
# where VALUE is true or false

python3 -m pypowerwall set -export VALUE
# where VALUE is battery_ok, pv_only, or never

[jasonacox]

Released as: https://pypi.org/project/pypowerwall/0.10.10/