IUtils<TDate>.date method should be more locale aware

Hi,

I was investigating the issue in different UI library that uses the date-io to abstract the date/time functionality (https://github.com/vuetifyjs/vuetify/issues/19803).

It seems, that authors uses the `adapter.date(...)` (where `adapter` is the selected implementation of the time management lib).

Unfortunatelly, that method seems, to only care for the date provided in the format `mm/dd/yyyy`.

Let's assume the following example:
* we have an input that allows to provide the date (as a string) in a specific format (depending of selected UI locale - en-us (mm/dd/yyyy) or polish (dd.mm.yyyy)
* some code will validate that value depending on the current locale
* if `adapter.date(...)` is used for the validation, then everything is OK if `en-us` is selected, but if other locale is selected (like `pl`), then the value inputed for the `adapter.date(...)` method should be validated against the pl locale format, not en

I think, that it will be just enough to extend the `date` method with some additional checks. The following is an example of the new `date` method implemenation for the `date-fns` interface, that should fix the issue (at least in a very common scenario).

```js
import DateFnsAdapter from '@date-io/date-fns';
import { isValid as dateFnsIsValid } from 'date-fns';

class BetterDateFnsAdapter extends DateFnsAdapter {
date(value) {
if (typeof value === "undefined") return new Date();
if (value === null) return null;

const defaultParsedValue = super.date(value);
if (dateFnsIsValid(defaultParsedValue)) return defaultParsedValue;

try {
let parseResult = this.parse(value, this.formats.keyboardDateTime24h);
if (dateFnsIsValid(parseResult)) return parseResult;

parseResult = this.parse(value, this.formats.keyboardDateTime);
if (dateFnsIsValid(parseResult)) return parseResult;

parseResult = this.parse(value, this.formats.keyboardDate);
if (dateFnsIsValid(parseResult)) return parseResult;
} catch {
// ignore
}

return defaultParsedValue;
}
}
```