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

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## Description

Closes: #9499 

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---

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- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [x] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
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- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
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- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

client/context.go

@@ -22,11 +22,9 @@ import (
 // Context implements a typical context created in SDK modules for transaction
 // handling and queries.
 type Context struct {
-	FromAddress sdk.AccAddress
-	Client      rpcclient.Client
-	ChainID     string
-	// Deprecated: Codec codec will be changed to Codec: codec.Codec
-	JSONCodec         codec.JSONCodec
+	FromAddress       sdk.AccAddress
+	Client            rpcclient.Client
+	ChainID           string
 	Codec             codec.Codec
 	InterfaceRegistry codectypes.InterfaceRegistry
 	Input             io.Reader
@@ -74,20 +72,8 @@ func (ctx Context) WithInput(r io.Reader) Context {
 	return ctx
 }
 
-// Deprecated: WithJSONCodec returns a copy of the Context with an updated JSONCodec.
-func (ctx Context) WithJSONCodec(m codec.JSONCodec) Context {
-	ctx.JSONCodec = m
-	// since we are using ctx.Codec everywhere in the SDK, for backward compatibility
-	// we need to try to set it here as well.
-	if c, ok := m.(codec.Codec); ok {
-		ctx.Codec = c
-	}
-	return ctx
-}
-
 // WithCodec returns a copy of the Context with an updated Codec.
 func (ctx Context) WithCodec(m codec.Codec) Context {
-	ctx.JSONCodec = m
 	ctx.Codec = m
 	return ctx
 }

client/keys/add_test.go

@@ -191,9 +191,9 @@ func Test_runAddCmdDryRun(t *testing.T) {
 			kb, err := keyring.New(sdk.KeyringServiceName(), keyring.BackendTest, kbHome, mockIn)
 			require.NoError(t, err)
 
-			appCodec := simapp.MakeTestEncodingConfig().Marshaler
+			appCodec := simapp.MakeTestEncodingConfig().Codec
 			clientCtx := client.Context{}.
-				WithJSONCodec(appCodec).
+				WithCodec(appCodec).
 				WithKeyringDir(kbHome).
 				WithKeyring(kb)
 			ctx := context.WithValue(context.Background(), client.ClientContextKey, &clientCtx)