Make search query for whether run has been published a shared function / reusable

[akachru-github]

• Every node gets an event, that has Analysis ID
  • "given this Analysis ID and the workflow URL, has this already been run?"
• Answer to this is a complicated query, but always the same. Look for Analysis ID, look for run, check if this has published Analysis.
• This query should not have to be re-written constantly. Let's put this in the Gateway, so we don't have to write this for each node, we reference a common function. This will standardize the query.