* refactor(types): refactor and add tests for checking Types
* remove unused
* uncomment
* use `Handler` in validator middleware
* remove unused
* create `src/validator` dir and move some files into it
* add the case that the context is in `validator`
* rename `D` to `S`
* feat: Another idea of validator middleware
* denoify
* set property value in constructor
* rename `option` to `options`
* add test for handling type error
* use `test` instead of `match`
* feat(middleware): introduce built-in Validator Middleware
* fixed type of `req.json()`
* Feat/builtin validator middleware another idea (#508)
* Enable overwriting of query/header data.
* Returns only verified data.
* rename `index.test.ts` to `middleware.test.ts`
* add `removeAdditional` option
* handling error that the JSON body is null
* tidy
* check is it string or not
* implement `isIn`
* enable validation the valies are duplicate
Co-authored-by: Taku Amano <taku@taaas.jp>