title: GenerateTableFetch drops flowfile on no data for query
body: <p>I am using using <code>GenerateTableFetch</code> with incoming flow files containing <code>table_name</code> to import data. And I have put <code>Additional WHERE clause</code> to handle incremental updates using <code>updated_at</code> column of the table manually. </p>
  
  <p>Issue is when there is no data to import for the constructed query, it simply drops the flow file. It should have a separate relationship other than success and failure for this case so that I can handle on my own if something has to be done for such cases.</p>
  
  <p>Currently, at the start of the workflow, I am using <code>Wait</code> on number of tables I have put into flow and tracking when they are done to increment the done count using <code>Notify</code>. But for the tables which get's dropped in <code>GenerateTableFetch</code>, it just keeps on waiting.</p>
  
  <p>Any way to handle this?</p>