[12.x] Add Rule::contains

[stevebauman]

Description

This PR adds a new Contains class and contains method to the Illuminate\Validation\Rule class.

It compiles into the existing contains validation rule string to check if an array contains all of the specified values.

Purpose

Laravel currently includes Rule::in(...) and Rule::array(...) to assist in creating their respective validation rules that contain enums, constants, and arrayables (collections, etc.). Having a method for the contains rule assists in this as well.

Usage

Before:

Validator::make($request->all(), [
    'roles' => [
        'required',
        'array',
        'contains:'.implode(',', array_column([Role::Admin, Role::Editor], 'value')),
    ],
]);

After:

Validator::make($request->all(), [
    'roles' => [
        'required',
        'array',
        Rule::contains([Role::Admin, Role::Editor]),
    ],
]);

[Muffinman]

Rule::enum() does already exist but I can see other cases where this would be useful.

[taylorotwell]

@stevebauman could you send a docs PR for this one?

[stevebauman]

@taylorotwell For sure!

[stevebauman]

Done: laravel/docs#10457

[patriziotomato]

@stevebauman doesnt that reference a method registered in orchestra? Not sure if that dependency is wanted.

[stevebauman]

@patriziotomato

framework/src/Illuminate/Collections/functions.php

Line 18 in 3d084e4

function enum_value($value, $default = null)