Fix KeyError exceptions when API returns unexpected response formats

[house2001]

Problem

The library throws KeyError exceptions when the ChargePoint API returns responses in unexpected formats. This causes integrations (like Home Assistant) to fail completely
rather than handling the errors gracefully.

Specific Errors:

1. KeyError: 'get_pandas' in get_home_chargers() at line 264
2. KeyError: 'get_panda_status' in get_home_charger_status() at line 320

Error Details

File "/usr/local/lib/python3.13/site-packages/python_chargepoint/client.py", line 264, in get_home_chargers
pandas = response.json()["get_pandas"]["device_ids"]
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
KeyError: 'get_pandas'

Root Cause

The code assumes the API will always return responses in the expected format:

• get_home_chargers() expects: {"get_pandas": {"device_ids": [...]}}
• get_home_charger_status() expects: {"get_panda_status": {...}}

However, the API may return different formats under certain conditions (authentication errors, empty results, API errors, etc.).

Solution

Add defensive error handling to gracefully handle unexpected response formats:

• Check if expected fields exist before accessing them
• Handle API error responses appropriately
• Return sensible defaults (empty lists) when the response format is unexpected
• Raise meaningful exceptions for actual errors

Testing

The expected API format still works correctly when tested directly, but fails in production environments, suggesting the API returns different response formats under
certain conditions.

[dacarson]

I am seeing this issue too. It would be great to get your PR merged.