Opt-in battery kWh sensors, bug fixes

Updated version with fixes.

• Estimated Battery Energy Sensors (Opt-in) (Only works if you have a battery installed)
  Estimated daily and total charge/discharge energy from batPower Solax data.
  The Solax Cloud API does not support battery kWh (energy) in their API, so we are calculating them from the battery W (Power) sensor.

You find these sensors disabled by default, under "Sensors" in your inverter, and in "System Totals" for now.
If we find that the data is accurate enough, we will enable them by default for systems with batteries.

If you use this feature, do let me know how it works, and how accurate it is, this would help a lot for future updates.
Let me know in GitHub Discussions

• Fixed daily battery kWh sensor metadata for HA statistics compatibility, Thank you @alan0000007 for testing! 👍
• Entity-prefix slug guarding improved.
• Energy yieldtoday and yieldtoday_total now use daily-energy semantics.

Full change log here: CHANGELOG