sqldb: add UpsertSelfNode query

This query is less strict in terms of the latest update timestamp field.
We want to be less strict with our own node data since we always want
our own updates recorded.

sqldb/sqlc/querier.go

@@ -147,6 +147,10 @@ type Querier interface {
 	UpsertNodeAddress(ctx context.Context, arg UpsertNodeAddressParams) error
 	UpsertNodeExtraType(ctx context.Context, arg UpsertNodeExtraTypeParams) error
 	UpsertPruneLogEntry(ctx context.Context, arg UpsertPruneLogEntryParams) error
+	// We use a separate upsert for our own node since we want to be less strict
+	// about the last_update field. For our own node, we always want to
+	// update the record even if the last_update is the same as what we have.
+	UpsertSourceNode(ctx context.Context, arg UpsertSourceNodeParams) (int64, error)
 	UpsertZombieChannel(ctx context.Context, arg UpsertZombieChannelParams) error
 }