refactor(expr): type-safe infallible evaluation #12921

3 / 4 tasks completed

1 task still to be completed

Task	Status
I have written necessary rustdoc comments	Completed
I have added necessary unit tests and integration tests	Completed
All checks passed in `./risedev check` (or alias, `./risedev c`)	Completed
My PR needs documentation updates. (Please use the Release note section below to summarize the impact on users)	Incomplete
Users may construct a `NonStrictExpression` in-place at any time with `new_topmost`. In this case, the inner will be a reference with lifetime.	Incomplete
However, in most of time it's an owned type stored in the executors. So giving a default type parameter makes it less verbose.	Incomplete