Extend eligible deals schema to enable adding DDO deals

[bajtos]

• Enhance fil-deal-ingester to store PieceCID and PieceSize alongside Label CID in the database of eligible deals.
• Add a new column to the database of eligible deals to distinguish between f05 and DDO deals.

See Spark & DDO deals and Spark DDO hack.

Tasks:

• spark-api - create a new table, eligible_deals, adding new columns on top of retrievable_deals schema. This way, we can migrate the schema & data incrementally.
  → feat: add table eligible_deals spark-api#485
• fil-deal-ingester - produce SQL to update eligible_deals table, set new columns for newly ingested deals
  → feat: switch to eligible_deals + set piece info #30
• manually run fil-deal-ingester to populate eligible_deals table, expand the filter to include all deals (not only recent)
• spark-api - update all code to use eligible_deals instead of retrievable_deals
• spark-api - drop retrievable_deals table after the change above was deployed