[11.x] Add Eloquent\Collection::findOrFail

[stevebauman]

Description

This PR adds a way to find a model in a collection (or throw an exception) with an already populated Eloquent collection.

Having this method available is handy in edge-case circumstances, and is also a nice to have for feature parity with the core Support\Collection instance (as it sports its own findOrFail method).

Usage

$users = User::get(); // [User(id: 1), User(id: 2)]

$users->findOrFail(1); // User

$user->findOrFail([]); // []

$user->findOrFail([1, 2]); // [User, User]

$user->findOrFail(3); // ModelNotFoundException: 'No query results for model [User] 3'

$user->findOrFail([1, 2, 3]); // ModelNotFoundException: 'No query results for model [User] 3'

Empty Collection Behaviour:

Since no models exist in the collection, there will be no message set, since a model cannot be determined.

$users = User::get(); // []

$users->findOrFail(); // ModelNotFoundException: ''