rpc: replace Amino with new JSON encoder (#4968)

Migrates the `rpc` package to use new JSON encoder in #4955. Branched off of that PR.

Tests pass, but I haven't done any manual testing beyond that. This should be handled as part of broader 0.34 testing.

node/node.go

@@ -15,7 +15,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/rs/cors"
 
-	amino "github.com/tendermint/go-amino"
 	dbm "github.com/tendermint/tm-db"
 
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -36,7 +35,6 @@ import (
 	"github.com/tendermint/tendermint/privval"
 	"github.com/tendermint/tendermint/proxy"
 	rpccore "github.com/tendermint/tendermint/rpc/core"
-	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	grpccore "github.com/tendermint/tendermint/rpc/grpc"
 	rpcserver "github.com/tendermint/tendermint/rpc/jsonrpc/server"
 	sm "github.com/tendermint/tendermint/state"
@@ -989,8 +987,6 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 	}
 
 	listenAddrs := splitAndTrimEmpty(n.config.RPC.ListenAddress, ",", " ")
-	coreCodec := amino.NewCodec()
-	ctypes.RegisterAmino(coreCodec)
 
 	if n.config.RPC.Unsafe {
 		rpccore.AddUnsafeRoutes()
@@ -1013,7 +1009,7 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 		mux := http.NewServeMux()
 		rpcLogger := n.Logger.With("module", "rpc-server")
 		wmLogger := rpcLogger.With("protocol", "websocket")
-		wm := rpcserver.NewWebsocketManager(rpccore.Routes, coreCodec,
+		wm := rpcserver.NewWebsocketManager(rpccore.Routes,
 			rpcserver.OnDisconnect(func(remoteAddr string) {
 				err := n.eventBus.UnsubscribeAll(context.Background(), remoteAddr)
 				if err != nil && err != tmpubsub.ErrSubscriptionNotFound {
@@ -1024,7 +1020,7 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 		)
 		wm.SetLogger(wmLogger)
 		mux.HandleFunc("/websocket", wm.WebsocketHandler)
-		rpcserver.RegisterRPCFuncs(mux, rpccore.Routes, coreCodec, rpcLogger)
+		rpcserver.RegisterRPCFuncs(mux, rpccore.Routes, rpcLogger)
 		listener, err := rpcserver.Listen(
 			listenAddr,
 			config,