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.

rpc/client/codec.go

@@ -1,13 +0,0 @@
-package client
-
-import (
-	amino "github.com/tendermint/go-amino"
-
-	"github.com/tendermint/tendermint/types"
-)
-
-var cdc = amino.NewCodec()
-
-func init() {
-	types.RegisterEvidences(cdc)
-}

rpc/client/http/http.go

@@ -8,9 +8,8 @@ import (
 	"sync"
 	"time"
 
-	amino "github.com/tendermint/go-amino"
-
 	"github.com/tendermint/tendermint/libs/bytes"
+	tmjson "github.com/tendermint/tendermint/libs/json"
 	"github.com/tendermint/tendermint/libs/log"
 	tmpubsub "github.com/tendermint/tendermint/libs/pubsub"
 	"github.com/tendermint/tendermint/libs/service"
@@ -138,11 +137,8 @@ func NewWithClient(remote, wsEndpoint string, client *http.Client) (*HTTP, error
 	if err != nil {
 		return nil, err
 	}
-	cdc := rc.Codec()
-	ctypes.RegisterAmino(cdc)
-	rc.SetCodec(cdc)
 
-	wsEvents, err := newWSEvents(cdc, remote, wsEndpoint)
+	wsEvents, err := newWSEvents(remote, wsEndpoint)
 	if err != nil {
 		return nil, err
 	}
@@ -479,7 +475,6 @@ var errNotRunning = errors.New("client is not running. Use .Start() method to st
 // WSEvents is a wrapper around WSClient, which implements EventsClient.
 type WSEvents struct {
 	service.BaseService
-	cdc      *amino.Codec
 	remote   string
 	endpoint string
 	ws       *jsonrpcclient.WSClient
@@ -488,9 +483,8 @@ type WSEvents struct {
 	subscriptions map[string]chan ctypes.ResultEvent // query -> chan
 }
 
-func newWSEvents(cdc *amino.Codec, remote, endpoint string) (*WSEvents, error) {
+func newWSEvents(remote, endpoint string) (*WSEvents, error) {
 	w := &WSEvents{
-		cdc:           cdc,
 		endpoint:      endpoint,
 		remote:        remote,
 		subscriptions: make(map[string]chan ctypes.ResultEvent),
@@ -505,7 +499,6 @@ func newWSEvents(cdc *amino.Codec, remote, endpoint string) (*WSEvents, error) {
 	if err != nil {
 		return nil, err
 	}
-	w.ws.SetCodec(w.cdc)
 	w.ws.SetLogger(w.Logger)
 
 	return w, nil
@@ -645,7 +638,7 @@ func (w *WSEvents) eventListener() {
 			}
 
 			result := new(ctypes.ResultEvent)
-			err := w.cdc.UnmarshalJSON(resp.Result, result)
+			err := tmjson.Unmarshal(resp.Result, result)
 			if err != nil {
 				w.Logger.Error("failed to unmarshal response", "err", err)
 				continue