reorg data extraction to prevent NoneType exceptions

[dan-s-github]

Reorganised the extraction of the json response values to prevent the NoneType exceptions that occur at midnight local time.

2023-11-22 00:03:14.647 ERROR (MainThread) [custom_components.alphaess] Unexpected error fetching alphaess data: 'NoneType' object has no attribute 'get'
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 290, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/config/custom_components/alphaess/coordinator.py", line 45, in _async_update_data
    _pv =  _onedateenergy.get("epv")
           ^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'get'

[CharlesGillanders]

The two separate sensors that both use SOC are a legacy from the web API - one sensor previously used a real time API and the other used a daily aggregate API. I left both sensors in place so as not to break anyone's existing automations.