update nlp-postgres user so NLP queries work

[cbarina]

Description

When trying to run Clarity, there was an issue with the postgres db login. Changing this from pg to postgres allowed creation of the clarity db, saving queries, and generation of query results.

[cbarina]

For some reason this also fixed frontend ui issues with ingest and websocket connection errors in upper right corner of dashboard via some combination of the following actions. After rebuilding containers with the updated postgres username and restarting via make start-clarity-localhost:

1. ran manual ingest with a python script from Utilities repo
2. stopped ingest* containers
3. tested ingest/nlpql with a few queries
4. out of curiosity restarted ingest* containers
5. no longer had websocket errors in upper right corner
6. uploaded sample csv file and mapped to default solr headers

It doesn't show up in the documents view/pie chart on the dashboard, but querying for the document source in the solr admin view shows it got added, and you can create a query off of it with the document source type.