FillStructWithDefault did not support setting default value recursively for nested struct

[zhangyuyu]

1. What version of Go and system type/arch are you using?

go version go1.21.3 darwin/arm64

2. What version of GoFrame are you using?

2.6.0

3. Can this issue be re-produced with the latest release?

yes

4. What did you do?

func main() {
	cfg := &Config{}

	gutil.FillStructWithDefault(cfg)
	fmt.Println(fmt.Sprintf("%+v", cfg))
}

// Config configuration for whole application
type Config struct {
	Name    string  `json:"name" d:"zhangsan"`
	Enable1 bool    `json:"enable1" d:"true"`
	Enable2 bool    `json:"enable2"`
	Service Service `json:"service"`
}

// Service configuration for service
type Service struct {
	Env         string `json:"env"`
	AppID       string `json:"appID" d:"testApp"` 
	IsDebug     bool   `json:"isDebug" d:"true"`  
	EnableCache bool   `json:"enable_cache"`  
}

5. What did you expect to see?

When struct Config have a nested struct Service, it can set default value for both Config and Service.
&{Name:zhangsan Enable1:true Enable2:false Service:{Env: AppID:testApp IsDebug:true EnableCache:false}}

6. What did you see instead?

It only set the default value for outer Struct Config, ignore the default tag for inner struct Service.
&{Name:zhangsan Enable1:true Enable2:false Service:{Env: AppID: IsDebug:false EnableCache:false}}

[github-actions]

Hello @zhangyuyu. We like your proposal/feedback and would appreciate a contribution via a Pull Request by you or another community member. We thank you in advance for your contribution and are looking forward to reviewing it!
你好 @zhangyuyu。我们喜欢您的提案/反馈，并希望您或其他社区成员通过拉取请求做出贡献。我们提前感谢您的贡献，并期待对其进行审查。