* Address #63874
* avoid setting _last_period to None
* name is always set in discovery
* ValueError never happens only DecimalException
* async_tariff_change tracks state change - state machine will not pass a None
* test we only reset one utility_meter
* test corrupted restored state
* pretty sure _current_tariff doesn't change from init until here
* missing assert
* Revert "async_tariff_change tracks state change - state machine will not pass a None"
This reverts commit 24fc04a964.
* address review comment
* always a Decimal
b211a1faa7