feat: Adds support for errors.py to also use 'errors' for error_details  (#1281)

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Fixes #1279 🦕
diff --git a/tests/test_http.py b/tests/test_http.py
index 4e61358..bfd9ba8 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -1587,7 +1587,7 @@
             "<HttpError 403 when requesting "
             "https://www.googleapis.com/someapi/v1/collection/?foo=bar returned "
             '"Access Not Configured". '
-            'Details: "Access Not Configured">'
+            "Details: \"[{'domain': 'usageLimits', 'reason': 'accessNotConfigured', 'message': 'Access Not Configured', 'debugInfo': 'QuotaState: BLOCKED'}]\">"
         )
         self.assertEqual(expected, str(callbacks.exceptions["2"]))