node: refactor package node (#21105)

This PR significantly changes the APIs for instantiating Ethereum nodes in
a Go program. The new APIs are not backwards-compatible, but we feel that
this is made up for by the much simpler way of registering services on
node.Node. You can find more information and rationale in the design
document: https://gist.github.com/renaynay/5bec2de19fde66f4d04c535fd24f0775.

There is also a new feature in Node's Go API: it is now possible to
register arbitrary handlers on the user-facing HTTP server. In geth, this
facility is used to enable GraphQL.

There is a single minor change relevant for geth users in this PR: The
GraphQL API is no longer available separately from the JSON-RPC HTTP
server. If you want GraphQL, you need to enable it using the
./geth --http --graphql flag combination.

The --graphql.port and --graphql.addr flags are no longer available.

p2p/simulations/http_test.go

@@ -64,12 +64,15 @@ type testService struct {
 	state atomic.Value
 }
 
-func newTestService(ctx *adapters.ServiceContext) (node.Service, error) {
+func newTestService(ctx *adapters.ServiceContext, stack *node.Node) (node.Lifecycle, error) {
 	svc := &testService{
 		id:    ctx.Config.ID,
 		peers: make(map[enode.ID]*testPeer),
 	}
 	svc.state.Store(ctx.Snapshot)
+
+	stack.RegisterProtocols(svc.Protocols())
+	stack.RegisterAPIs(svc.APIs())
 	return svc, nil
 }
 
@@ -126,7 +129,7 @@ func (t *testService) APIs() []rpc.API {
 	}}
 }
 
-func (t *testService) Start(server *p2p.Server) error {
+func (t *testService) Start() error {
 	return nil
 }
 
@@ -288,7 +291,7 @@ func (t *TestAPI) Events(ctx context.Context) (*rpc.Subscription, error) {
 	return rpcSub, nil
 }
 
-var testServices = adapters.Services{
+var testServices = adapters.LifecycleConstructors{
 	"test": newTestService,
 }