refactor!: Remove clientCtx.JSONCodec and rename EncodingConfig.Marshaler to Codec (#9521)

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## Description

Closes: #9499 

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- [ ] confirmed `!` in the type prefix if API or client breaking change
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x/auth/client/cli/encode_test.go

@@ -39,7 +39,7 @@ func TestGetCommandEncode(t *testing.T) {
 	ctx := context.Background()
 	clientCtx := client.Context{}.
 		WithTxConfig(encodingConfig.TxConfig).
-		WithCodec(encodingConfig.Marshaler)
+		WithCodec(encodingConfig.Codec)
 	ctx = context.WithValue(ctx, client.ClientContextKey, &clientCtx)
 
 	cmd.SetArgs([]string{txFileName})
@@ -52,7 +52,7 @@ func TestGetCommandDecode(t *testing.T) {
 
 	clientCtx := client.Context{}.
 		WithTxConfig(encodingConfig.TxConfig).
-		WithCodec(encodingConfig.Marshaler)
+		WithCodec(encodingConfig.Codec)
 
 	cmd := GetDecodeCommand()
 	_ = testutil.ApplyMockIODiscardOutErr(cmd)