SFCORE-3435: Handle upload document operation

[Aurelieluciani]

Link to the issue

https://shopping-feed.atlassian.net/browse/SFCORE-3435

Reason for this PR

Add back functionality to manage upload document operation, inadvertently deleted in this PR: #119

What does the PR do

Restore the deleted code, than add the compatibility with the new version.

How to test

<?php
namespace ShoppingFeed\Sdk;

use Throwable;

require 'vendor/autoload.php';

// API client configuration
$apiUrl = 'http://localhost';
$token  = '<TOKEN>';

// Order configuration
$reference   = '#1A';
$channel     = 'amazon';
$id          = 1234;
$invoiceFile = '<PATH>/invoice.pdf';

$credential = new Credential\Token($token);
$options    = (new Client\ClientOptions())->setBaseUri($apiUrl);

# Deprecated old version
# $operation = new Api\Order\OrderOperation();
# $operation->uploadDocument($reference, $channel, new Api\Order\Document\Invoice($invoiceFile));

# New version
$operation = new Api\Order\Operation();
$operation->uploadDocument(new Id($id), new Api\Order\Document\Invoice($invoiceFile));

$orderApi = Client\Client::createSession($credential, $options)->getMainStore()->getOrderApi();
$orderApi->execute($operation);