refactor: use viper unmarshal in config.GetConfig function (#13651)

## Description

Closes: #13606

---

### Author Checklist

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please add links to any relevant follow up issues.*

I have...

- [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/main/CONTRIBUTING.md#pr-targeting))
- [x] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/main/docs/building-modules)
- [x] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/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
- [x] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] 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)

CHANGELOG.md

@@ -82,6 +82,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [#13178](https://github.com/cosmos/cosmos-sdk/pull/13178) Add `cosmos.msg.v1.service` protobuf annotation to allow tooling to distinguish between Msg and Query services via reflection. 
 * [#13236](https://github.com/cosmos/cosmos-sdk/pull/13236) Integrate Filter Logging
 * [#13528](https://github.com/cosmos/cosmos-sdk/pull/13528) Update `ValidateMemoDecorator` to only check memo against `MaxMemoCharacters` param when a memo is present.
+* [#13651](https://github.com/cosmos/cosmos-sdk/pull/13651) Update `server/config/config.GetConfig` function.
 
 ### State Machine Breaking
 

server/config/config.go

@@ -293,83 +293,11 @@ func DefaultConfig() *Config {
 
 // GetConfig returns a fully parsed Config object.
 func GetConfig(v *viper.Viper) (Config, error) {
-	globalLabelsRaw, ok := v.Get("telemetry.global-labels").([]interface{})
-	if !ok {
-		return Config{}, fmt.Errorf("failed to parse global-labels config")
+	conf := DefaultConfig()
+	if err := v.Unmarshal(conf); err != nil {
+		return Config{}, fmt.Errorf("error extracting app config: %w", err)
 	}
-
-	globalLabels := make([][]string, 0, len(globalLabelsRaw))
-	for idx, glr := range globalLabelsRaw {
-		labelsRaw, ok := glr.([]interface{})
-		if !ok {
-			return Config{}, fmt.Errorf("failed to parse global label number %d from config", idx)
-		}
-		if len(labelsRaw) == 2 {
-			globalLabels = append(globalLabels, []string{labelsRaw[0].(string), labelsRaw[1].(string)})
-		}
-	}
-
-	return Config{
-		BaseConfig: BaseConfig{
-			MinGasPrices:        v.GetString("minimum-gas-prices"),
-			InterBlockCache:     v.GetBool("inter-block-cache"),
-			Pruning:             v.GetString("pruning"),
-			PruningKeepRecent:   v.GetString("pruning-keep-recent"),
-			PruningInterval:     v.GetString("pruning-interval"),
-			HaltHeight:          v.GetUint64("halt-height"),
-			HaltTime:            v.GetUint64("halt-time"),
-			IndexEvents:         v.GetStringSlice("index-events"),
-			MinRetainBlocks:     v.GetUint64("min-retain-blocks"),
-			IAVLCacheSize:       v.GetUint64("iavl-cache-size"),
-			IAVLDisableFastNode: v.GetBool("iavl-disable-fastnode"),
-			AppDBBackend:        v.GetString("app-db-backend"),
-		},
-		Telemetry: telemetry.Config{
-			ServiceName:             v.GetString("telemetry.service-name"),
-			Enabled:                 v.GetBool("telemetry.enabled"),
-			EnableHostname:          v.GetBool("telemetry.enable-hostname"),
-			EnableHostnameLabel:     v.GetBool("telemetry.enable-hostname-label"),
-			EnableServiceLabel:      v.GetBool("telemetry.enable-service-label"),
-			PrometheusRetentionTime: v.GetInt64("telemetry.prometheus-retention-time"),
-			GlobalLabels:            globalLabels,
-		},
-		API: APIConfig{
-			Enable:             v.GetBool("api.enable"),
-			Swagger:            v.GetBool("api.swagger"),
-			Address:            v.GetString("api.address"),
-			MaxOpenConnections: v.GetUint("api.max-open-connections"),
-			RPCReadTimeout:     v.GetUint("api.rpc-read-timeout"),
-			RPCWriteTimeout:    v.GetUint("api.rpc-write-timeout"),
-			RPCMaxBodyBytes:    v.GetUint("api.rpc-max-body-bytes"),
-			EnableUnsafeCORS:   v.GetBool("api.enabled-unsafe-cors"),
-		},
-		Rosetta: RosettaConfig{
-			Enable:              v.GetBool("rosetta.enable"),
-			Address:             v.GetString("rosetta.address"),
-			Blockchain:          v.GetString("rosetta.blockchain"),
-			Network:             v.GetString("rosetta.network"),
-			Retries:             v.GetInt("rosetta.retries"),
-			Offline:             v.GetBool("rosetta.offline"),
-			EnableFeeSuggestion: v.GetBool("rosetta.enable-fee-suggestion"),
-			GasToSuggest:        v.GetInt("rosetta.gas-to-suggest"),
-			DenomToSuggest:      v.GetString("rosetta.denom-to-suggest"),
-		},
-		GRPC: GRPCConfig{
-			Enable:         v.GetBool("grpc.enable"),
-			Address:        v.GetString("grpc.address"),
-			MaxRecvMsgSize: v.GetInt("grpc.max-recv-msg-size"),
-			MaxSendMsgSize: v.GetInt("grpc.max-send-msg-size"),
-		},
-		GRPCWeb: GRPCWebConfig{
-			Enable:           v.GetBool("grpc-web.enable"),
-			Address:          v.GetString("grpc-web.address"),
-			EnableUnsafeCORS: v.GetBool("grpc-web.enable-unsafe-cors"),
-		},
-		StateSync: StateSyncConfig{
-			SnapshotInterval:   v.GetUint64("state-sync.snapshot-interval"),
-			SnapshotKeepRecent: v.GetUint32("state-sync.snapshot-keep-recent"),
-		},
-	}, nil
+	return *conf, nil
 }
 
 // ValidateBasic returns an error if min-gas-prices field is empty in BaseConfig. Otherwise, it returns nil.