fix: electrolux chillflex pro exp34u339hw

Thanks for the project!

I was able to run the application, but encountered the following log error: Error getting appliance state:
It appears that the appliance state for the model ELECTROLUX ChillFlex Pro EXP34U339HW differs slightly from the expected format.

To resolve this, I made updates in this merge request. Adjusted the Appliance and SanitizedState types to mark certain properties as nullable to handle the unexpected structure in the payload.

Here is a sample JSON payload that triggered the issue: case.json