text: Title: Simplifying Open Source Contributions Through Operator Tiering from Dev aspect
  Body: ### Search before continuing 先搜索，再继续
  
  - [X] I have searched the Data-Juicer issues and found no similar feature requests. 我已经搜索了 Data-Juicer 的 issue 列表但是没有发现类似的功能需求。
  
  
  ### Description 描述
  
  ### Current state
  The complete process for developing an operator can be quite demanding. This involves many things like 
  - adhering to coding styles 
  - adding new StatsKeys 
  - creating a new operator file, considering decorators, unified model management of HF, handling batched operations, managing paths for Mapper operators
  -  writing unit tests
  -  documenting the operator
  -  and ensuring it is fusible. 
  
  Although some of these steps are optional and can be automatically finished, they present additional cognitive and development burdens for new contributors, especially when compared to writing a simple demo operator from scratch.
  
  ### A potential solution
  
  To reduce the entry barriers, I propose implementing a tiered labeling system for operators, such as `alpha_op`, `beta_op`, and `stable_op`.
  
  - Alpha Operators: Only need to showcase new functionalities and serve as simple demos contributed by the community.
  - Beta Operators: Must meet the mandatory requirements outlined in the DJ-developer guide.
  - Stable Operators: In addition to satisfying beta_op criteria, they should fulfill optional recommendations in the DJ-developer guide, and write and pass both single-node and distributed unit tests.
  
  Welcome better suggestions and more detailed implementation plans to enhance this proposal further.
  
  
  
  ### Use case 使用场景
  
  _No response_
  
  ### Additional 额外信息
  
  _No response_
  
  ### Are you willing to submit a PR for this feature? 您是否乐意为此功能提交一个 PR？
  
  - [X] Yes I'd like to help by submitting a PR! 是的！我愿意提供帮助并提交一个PR！