graph/db+sqldb: validate prune log migration using batching

As was done in the previous commits for nodes & channels, we update the
migratePruneLog function here so that it validates migrated entries in
batches rather than one-by-one.

graph/db/sql_store.go

@@ -142,6 +142,7 @@ type SQLQueries interface {
 	*/
 	GetPruneTip(ctx context.Context) (sqlc.GraphPruneLog, error)
 	GetPruneHashByHeight(ctx context.Context, blockHeight int64) ([]byte, error)
+	GetPruneEntriesForHeights(ctx context.Context, heights []int64) ([]sqlc.GraphPruneLog, error)
 	UpsertPruneLogEntry(ctx context.Context, arg sqlc.UpsertPruneLogEntryParams) error
 	DeletePruneLogEntriesInRange(ctx context.Context, arg sqlc.DeletePruneLogEntriesInRangeParams) error