Implement bbs_database upload-elasticsearch

[FrancescoCasalegno]

Context

• In our bbs_database commands implementing the literature ETL pipeline, we currently have a subcommand add for uploading to the MySQL database.
• But since we now want to use Elasticsearch instead of a SQL db, we need a command that allows to upload to Elasticsearch.

Actions

• Is upload-elasticsearch a good name, or can we find anything better? upload-es? add-elasticsearch? ...
• Implement command upload-elasticsearch to upload the JSON parse paragraphs + article metadata in the respective Elasticsearch tables.
• Notice that we decided to upload paragraphs, not sentences (different from what done in the past!).
• The article metadata uploaded on Elasticsearch should include topics info.

Dependencies

• Add Elasticsearch articles table #618 – We need the table articles to be created in Elasticsearch database.
• Include topic info in JSON output parse of bbs_database parse #619 – We need the JSON parse to include information about the topic.