Refactor Carbon static calls to Date Facade

[imliam]

Laravel's Date facade has some benefits; notably that it adheres to whatever handler is configured (so if you call Date::use(CarbonImmutable::class) in a service provider, all your dates will be immutable).

- Carbon::now();
+ Date::now();

[Tamas-hi]

RectorPHP has a prepared set called "carbon" that converts datetime to carbon.
I think we have a conflict here, and makes it harder for the end user which one to use.