p2p: change default to use new stack (#6862)

This is just a configuration change to default to using the new stack
unless explicitly disabled (e.g. `UseLegacy`) this renames the
configuration value and makes the configuration logic more clear.

The legacy option is good to retain as a fallback if the new stack has
issues operationally, but we should make sure that most of the time
we're using the new stack.

node/node_test.go

@@ -43,6 +43,7 @@ import (
 
 func TestNodeStartStop(t *testing.T) {
 	config := cfg.ResetTestRoot("node_node_test")
+
 	defer os.RemoveAll(config.RootDir)
 
 	// create & start node
@@ -53,8 +54,6 @@ func TestNodeStartStop(t *testing.T) {
 	n, ok := ns.(*nodeImpl)
 	require.True(t, ok)
 
-	t.Logf("Started node %v", n.sw.NodeInfo())
-
 	// wait for the node to produce a block
 	blocksSub, err := n.EventBus().Subscribe(context.Background(), "node_test", types.EventQueryNewBlock)
 	require.NoError(t, err)