Delete objects from ES before loading from object database

When syncing from scratch or re-syncing, for the object types that are enabled to be stored in ES, always delete all objects from ES first on node startup.
Otherwise, if the es-objects-sync-db-on-startup startup option is true, for the object types that are enabled to be stored in ES and both no-delete and store-updates options are false, delete all objects from ES before loading from the object database.

bitshares / bitshares-core