sqldb/sqlc: update graph CreateChannel query for v2

Add three new optional fields to the CreateChannel SQL query to
support v2 channel announcements:
- signature: single schnorr signature (replaces four ECDSA sigs)
- funding_pk_script: the funding output script
- merkle_root_hash: for taproot channels

These fields are NULL for v1 channels and populated for v2 channels.

sqldb/sqlc/queries/graph.sql

@@ -297,9 +297,9 @@ INSERT INTO graph_channels (
     version, scid, node_id_1, node_id_2,
     outpoint, capacity, bitcoin_key_1, bitcoin_key_2,
     node_1_signature, node_2_signature, bitcoin_1_signature,
-    bitcoin_2_signature
+    bitcoin_2_signature, signature, funding_pk_script, merkle_root_hash
 ) VALUES (
-    $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12
+    $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15
 )
 RETURNING id;