[11.x] Adds support for int backed enums to implicit Enum route binding

[monurakkaya]

This pull request allows you to bind int backed enums to your routes.

// Assuming the following `Enum`
enum DocumentType: int
{
    case ANNUAL_WORK_PLAN = 1;
    case ANNUAL_TRAINING_PLAN = 2;
}

// And assuming the following route;
Route::get('/documents/{documentType}', function (DocumentType $documentType) {
    return $documentType->name;
});

now, if we try to bind int backed enum to route, we are getting the error below :

Illuminate\Contracts\Container\BindingResolutionException

Target [App\Enums\DocumentType] is not instantiable.

With this PR we'll see:

// GET `/documents/1` returns `ANNUAL_WORK_PLAN`...
// GET `/documents/2` returns `ANNUAL_TRAINING_PLAN`...
// GET `/documents/3` returns `404 Not Found`...
// GET `/documents/test` returns `404 Not Found`... <- I'm not sure if we should give 404 here

There is a comment about why we didn't do it in the first place but I don't see any reason to not to try that.

We can skip checking the backed enum type in the ReflectionEnum part and validate all values via collect($backedEnum::cases)->first() without a match

And also I've created a PR for the docs

Best.

[driesvints]

This seems to have broken some apps: #51114

[taylorotwell]

Sorry @monurakkaya - looks like this will have to go to master branch for Laravel 12