(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/datastore/postgres/repositories/header_repository.go

@@ -52,7 +52,7 @@ func (repository HeaderRepository) CreateOrUpdateHeader(header core.Header) (int
 
 func (repository HeaderRepository) GetHeader(blockNumber int64) (core.Header, error) {
 	var header core.Header
-	err := repository.database.Get(&header, `SELECT block_number, hash, raw FROM headers WHERE block_number = $1 AND eth_node_fingerprint = $2`,
+	err := repository.database.Get(&header, `SELECT id, block_number, hash, raw, block_timestamp FROM headers WHERE block_number = $1 AND eth_node_fingerprint = $2`,
 		blockNumber, repository.database.Node.ID)
 	return header, err
 }

pkg/datastore/postgres/repositories/header_repository_test.go

@@ -188,9 +188,11 @@ var _ = Describe("Block header repository", func() {
 			dbHeader, err := repo.GetHeader(header.BlockNumber)
 
 			Expect(err).NotTo(HaveOccurred())
+			Expect(dbHeader.Id).NotTo(BeZero())
 			Expect(dbHeader.BlockNumber).To(Equal(header.BlockNumber))
 			Expect(dbHeader.Hash).To(Equal(header.Hash))
 			Expect(dbHeader.Raw).To(MatchJSON(header.Raw))
+			Expect(dbHeader.Timestamp).To(Equal(header.Timestamp))
 		})
 
 		It("does not return header for a different node fingerprint", func() {