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/connect_test.go

@@ -26,8 +26,8 @@ import (
 
 func newTestNetwork(t *testing.T, nodeCount int) (*Network, []enode.ID) {
 	t.Helper()
-	adapter := adapters.NewSimAdapter(adapters.Services{
-		"noopwoop": func(ctx *adapters.ServiceContext) (node.Service, error) {
+	adapter := adapters.NewSimAdapter(adapters.LifecycleConstructors{
+		"noopwoop": func(ctx *adapters.ServiceContext, stack *node.Node) (node.Lifecycle, error) {
 			return NewNoopService(nil), nil
 		},
 	})