Graceful handling of invalid JSON

[Luwdo]

I would like for JSON parse failures to result in a 400 bad request invalid JSON.

For example

    @Post('/foo')
    async deleteFoo(@Body({ format: 'json' }) id: string) {
       return {"result":"success"}
    }

If I POST with a body that is not valid JSON it would result in a 400 bad request.

[rezonant]

As of latest patch release, it returns 500. Let's leave this open to ensure we get 400 for this specific case.