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.

cmd/p2psim/main.go

@@ -289,7 +289,7 @@ func createNode(ctx *cli.Context) error {
 		config.PrivateKey = privKey
 	}
 	if services := ctx.String("services"); services != "" {
-		config.Services = strings.Split(services, ",")
+		config.Lifecycles = strings.Split(services, ",")
 	}
 	node, err := client.CreateNode(config)
 	if err != nil {