rpc/client: take context as first param (#5347)

Closes #5145

also applies to light/client

node/node.go

@@ -564,7 +564,10 @@ func startStateSync(ssR *statesync.Reactor, bcR fastSyncReactor, conR *cs.Reacto
 
 	if stateProvider == nil {
 		var err error
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
 		stateProvider, err = statesync.NewLightClientStateProvider(
+			ctx,
 			state.ChainID, state.Version, state.InitialHeight,
 			config.RPCServers, light.TrustOptions{
 				Period: config.TrustPeriod,