(VDB-298) Consume Pit contract storage diffs

- Continuously parse storage diffs CSV data to read Pit contract state
- Convert ilks in database to raw bytes32 value for use in generating
  storage keys dynamically
- Persist storage diffs with block number and hash for validation

pkg/transformers/shared/storage/transformer.go

@@ -0,0 +1,14 @@
+package storage
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/storage_diffs/shared"
+)
+
+type Transformer interface {
+	Execute(row shared.StorageDiffRow) error
+	ContractAddress() common.Address
+}
+
+type TransformerInitializer func(db *postgres.DB) Transformer