[Development] Build job to continuously embed newly ingested tweets

[AbrahamSanders]

Requirements:

• Should run in the background* as a cron job or a service

• Should cyclically query Elasticsearch** for all tweets that have not been embedded, processing chunks of K tweets at a time.

• The text for each tweet should be cleaned and then embedded using Universal Sentence Encoder

• The vectors should be updated back to elasticsearch using a partial bulk index per chunk.

• We don't want to embed the tweets immediately as they are received from the Twitter stream API because we don't want to synchronously bog down the twitter_monitor process. Doing so would reduce our ingestion throughput and risk causing full buffer disconnects from the Twitter side.

** Note: this requires Elasticsearch 7.x for support of the dense_vector field type.

[AbrahamSanders]

This is done in 8eaf0c4f0e5b68b2834c19d33cb9999cd0f582a7