Add Laravel HTTP Client macros to consume JSON:API documents

[JaZo]

Description

I've added JSON:API macros to the Laravel HTTP Client.

use Illuminate\Support\Facades\Http;
use Swis\JsonApi\Client\Facades\DocumentFactoryFacade;
use Swis\JsonApi\Client\Item;

$recipe = (new Item())
    ->setType('recipes')
    ->fill([
        'title' => 'Frankfurter salad with mustard dressing',
    ]);

$document = Http::asJsonApi() // Sets the Content-Type and Accept headers to 'application/vnd.api+json'.
    ->post('https://cms.contentacms.io/api/recipes', DocumentFactoryFacade::make($recipe))
    ->jsonApi(); // Parses the response into a JSON:API document.

Motivation and context

This makes it easy to work with JSON:API documents using the Http facade.

How has this been tested?

Copied from a project where I've used these macros.

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

• I have read the CONTRIBUTING document.
• My pull request addresses exactly one patch/feature.
• I have created a branch for this patch/feature.
• Each individual commit in the pull request is meaningful.
• I have added tests to cover my changes.
• If my change requires a change to the documentation, I have updated it accordingly.

[bbrala]

Looks good :)