Fixes #6935

Context

When a stream emits the 'aborted' event after headers are received, the response object becomes inaccessible, leading to a missing err.response. This change ensures that key response data, including the body content received so far, is captured early and included in the resulting error object for better error handling and debugging.

Fix Summary

• Tracks response metadata (status, statusText, headers, req) and incoming data chunks once headers are received.
• Constructs a partialResponse (with body as data) and attaches it via AxiosError.from(...) inside responseStream.on('aborted') and req.on('error') (if headers were already received)

Testing

• Added new unit test: 'should expose partial response on aborted stream', which confirms that err.response includes status, headers, and partial data

Suggestions & Questions

This appears to be the first implementation in Axios that manually preserves and surfaces partial response data for error scenarios where the original response object is inaccessible. I'd appreciate any input on the overall design.

• It's currently capturing status, statusText, headers, req, and data. Would there be more fields to capture?
• Would it be valuable to add a isPartial: true flag in the error response object to denote that the response is incomplete?