graph/db: convert other node CRUD methods

Convert a few more CRUD methods to handle v2 nodes. Then update some
more tests to be run against both v1 and v2 nodes.

routing/router_test.go

@@ -132,7 +132,7 @@ func createTestCtxFromGraphInstanceAssumeValid(t *testing.T,
 	)
 	require.NoError(t, err)
 
-	sourceNode, err := graphInstance.graph.SourceNode(t.Context())
+	sourceNode, err := graphInstance.v1Graph.SourceNode(t.Context())
 	require.NoError(t, err)
 	sessionSource := &SessionSource{
 		GraphSessionFactory: graphInstance.graph,
@@ -1205,7 +1205,7 @@ func TestFindPathFeeWeighting(t *testing.T) {
 	var preImage [32]byte
 	copy(preImage[:], bytes.Repeat([]byte{9}, 32))
 
-	sourceNode, err := ctx.graph.SourceNode(t.Context())
+	sourceNode, err := ctx.v1Graph.SourceNode(t.Context())
 	require.NoError(t, err, "unable to fetch source node")
 
 	amt := lnwire.MilliSatoshi(100)
@@ -1216,7 +1216,7 @@ func TestFindPathFeeWeighting(t *testing.T) {
 	// the edge weighting, we should select the direct path over the 2 hop
 	// path even though the direct path has a higher potential time lock.
 	path, err := dbFindPath(
-		ctx.graph, nil, &mockBandwidthHints{},
+		ctx.v1Graph, nil, &mockBandwidthHints{},
 		noRestrictions,
 		testPathFindingConfig,
 		sourceNode.PubKeyBytes, target, amt, 0, 0,