PR for #2464.

Features:

• Add new option es-objects-sync-db-on-startup to copy all applicable objects from the object database (chain state) to ES on program startup
• Deprecate the es-objects-keep-only-current option, add new options
  • es-objects-accounts-store-updates, default false
  • es-objects-assets-store-updates, default false
  • es-objects-asset-bitasset-store-updates, default false
  • es-objects-balances-store-updates, default false
  • es-objects-proposals-store-updates, default false
  • es-objects-proposals-no-delete, default true
  • es-objects-limit-orders-store-updates, default false
  • es-objects-limit-orders-no-delete, default false
• Update default value of es-objects-limit-orders to true

Done some code cleanups and refactory.

Tasks:

• sync (objects in) ES database from node on startup via --es-objects-sync-db-on-startup option
• deal with errors on deletion i.e. data does not exist in ES due to out of sync: { ..., "errors":false, "items":[{"delete":{ ..., "result":"not_found", ..., "status":404}}, ... ]}
• deprecate the keep-only-current option, add dedicated store-updates and no-delete options for each applicable object