accounts, cmd, internal: disable unlock account on open HTTP (#17037)

* cmd, accounts, internal, node, rpc, signer: insecure unlock protect

* all: strict unlock API by rpc

* cmd/geth: check before printing warning log

* accounts, cmd/geth, internal: tiny polishes

node/service.go

@@ -68,6 +68,12 @@ func (ctx *ServiceContext) Service(service interface{}) error {
 	return ErrServiceUnknown
 }
 
+// ExtRPCEnabled returns the indicator whether node enables the external
+// RPC(http, ws or graphql).
+func (ctx *ServiceContext) ExtRPCEnabled() bool {
+	return ctx.config.ExtRPCEnabled()
+}
+
 // ServiceConstructor is the function signature of the constructors needed to be
 // registered for service instantiation.
 type ServiceConstructor func(ctx *ServiceContext) (Service, error)