Output to CSV

[stwiname]

As well as outputting data to Postgres there should be an option to output to CSV as well. This will allow other DBs to import data.

Requirements:

• Data should be output to CSV as well as to Postgres
• Option can be enabled via a CLI flag for a directory path
• Each entity should have its own file
• It should only append data, no deletions or updates, but entities with the same id can be entered multiple times
• Initially all data should be stored in a single file for an entity but later on we could support:
  • File rotation
  • Splitting files by block range