feat: add a helper macro to reduce the definition of root methods

[yjhmelody]

Which issue does this PR close?

Closes #.

Rationale for this change

To reduce boilerplate code; align the behaviors and docs.

What changes are included in this PR?

Are there any user-facing changes?

[Xuanwo]

Thank you very much for your effort. However, OpenDAL aims to optimize code for readability. Repeating the code for root that doesn't change frequently is allowed and encouraged. Additionally, we prefer to avoid using macros whenever possible.

[yjhmelody]

it is just simple optional macro

[Xuanwo]

it is just simple optional macro

Thanks, but I don't want it.

---

We have a long-term goal to generate code for configuration and builders, but we are still working out the details: #4279

There is another idea that moving root to operator side: #4774

We often address problems in other ways instead of introducing macros, even when it's simple.

[yjhmelody]

fine