fix: improve error handling for invalid API responses

[brandonhawi]

Error Handling Improvement

This PR improves error handling when the NBA API returns invalid or empty responses.

Problem

The NBA API sometimes returns non-JSON responses for certain date/parameter combinations:

• Empty responses for dates with no data
• 500 Internal Server Error messages wrapped in plain text
• Previously resulted in cryptic JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Solution

Enhanced NBAResponse.get_dict() in src/nba_api/library/http.py to:

• Catch JSONDecodeError and provide informative error messages
• Show preview of response content when invalid JSON is received
• Include the request URL for easier debugging
• Differentiate between empty responses and responses with error content

Example

Before:

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

After:

ValueError: NBA API returned an invalid JSON response: Expecting value: line 1 column 1 (char 0). 
Response content (first 200 chars): System.Net.WebException: The remote server returned an error: (500) Internal Server Error...
URL: https://stats.nba.com/stats/playerdashptreb?...

Testing

• All 460 existing unit tests pass
• Tested with various date/season combinations showing different API quirks

[swar]

My thoughts on this MR is that the exception messages are too long. I think the exception messages should be a short summary. I think all the additional context is great, but I think it might need too be an exception attribute instead.

I think I would be okay with making custom exceptions in this case. If we strive towards that, maybe we should think about bumping the version to 1.12.0 since it could be a breaking change for folks.