[7.x] Add apiResource in RouteRegistrar

[LasseRafn]

Since Laravel 7.X has a new (optimized) routing implemented, route names are more important, and caching routes will break if naming collisions happen.

Normally you can use Route::name('posts')->resource(..... to change the name of a group (useful for nested routes like: /posts/{post}/comments)

HOWEVER, this is not possible with apiResource.

I propose this change to allow that. Its just a convenience to replace:

Route::name('posts')->resource('posts/{post}/comments', 'PostCommentsController')->only(['index', 'show', 'store', 'update', 'destroy']);

With:

Route::name('posts')->apiResource('posts/{post}/comments', 'PostCommentsController');