[Tech Request]: clean plan code

### Is there an existing issue for the same tech request?

- [X] I have checked the existing issues.

### Does this tech request not affect user experience?

- [X] This tech request doesn't affect user experience.

### What would you like to be added ?

1，plan验证
- 正确性验证

- stable验证
同一个select 迭代过程中前后一致或者符合预期的修改。

- random sql test
随机生成select 测试plan正确性或结果正确性。与mysql等对比。

2, clean code
- 拆分高耦合的代码
- 简化复杂函数

### Why is this needed ?

1， 降低维护门槛。让更多成员能参与plan的迭代。
2，提升代码质量。降低故障率，提升问题响应效率。
3，提升业务开发效率。减少团队单点，提升业务推进效率。

### Additional information

_No response_