Add More Error Logging When Indexing Fails

[jvanderen1]

In trying to debug an issue, I needed to add more logging to PGSync in order to see the problem. This PR adds additional logging similar to this one within the Elasticsearch community.

Before, I would see messages like:

BulkIndexError: ('1 document(s) failed to index.')

While this did indicate something was wrong with the document, I did not know which one or why it was problematic. With this change, I now see errors containing:

{..., 'reason': 'Document contains at least one immense term in field="description" ...}

This along with additional information such as the document shape (including id) have been valuable information.

Note: This logging will only be visible with ELASTICSEARCH_RAISE_ON_ERROR="false" and ELASTICSEARCH_RAISE_ON_EXCEPTION="false". This was thanks to the suggestion within #503 (comment)

[toluaina]

nice! wish I'd have thought of that