Need an assertion policy

Currently, we use `debug_assert` in most cases because we check the assertions in tests and we don't want to check them again in the release binary.

But it's not sustainable. Bugs will occur for any reason. It seems better to use `assert` to crash early because we have a plan to add [a bug tracker](https://github.com/CodeChain-io/codechain/issues/196).

I think we need a guideline to decide when to use `assert` or `debug_assert`.

首先检查整个 Rust 代码库中当前对 `assert` 和 `debug_assert` 的使用情况，因为 issue 没有指定具体的文件或测试。定义项目在两者之间进行选择的指南，并将其记录在项目中适当的指南位置；当该策略足够清晰、能够一致地应用时，即视为完成。

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