Sync only missing blocks on cold import

= Add eth_node_fingerprint to block that can be imitated by both hot and cold imports
- Only sync missing blocks (blocks that are missing or don't share a fingerprint) on cold import
- Set block is_final status after import

pkg/crypto/parser.go

@@ -0,0 +1,21 @@
+package crypto
+
+import (
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+type PublicKeyParser interface {
+	ParsePublicKey(privateKey string) (string, error)
+}
+
+type EthPublicKeyParser struct{}
+
+func (EthPublicKeyParser) ParsePublicKey(privateKey string) (string, error) {
+	np, err := crypto.HexToECDSA(privateKey)
+	if err != nil {
+		return "", err
+	}
+	pubKey := discover.PubkeyID(&np.PublicKey)
+	return pubKey.String(), nil
+}