Implement authentication error handling in client.py

[vivan070707-ctrl]

Added error handling for 401 and 403 status codes.

[vivan070707-ctrl]

Updated implementation in _request_json as suggested. Please review.

[George-iam]

Thanks for the effort! However this PR has a couple of issues:

1. The auth check is inside the retry loop in _request_json() - but auth failures should not be retried (they'll fail the same way every time).
2. This duplicates the logic already in _raise_http_error() which is called further down the flow.
3. Missing **kwargs in AxmeAuthError() - loses body, request_id, trace_id.

PR #41 is the better approach (fixing _raise_http_error). Let's focus the work there. Closing this one in favor of #41.