Add Mollie API integration and webhook for software upgrade payments

- Introduced the `CaBundle.php` class for managing CA certificates.
- Updated `installed.json` and `installed.php` to include the new `composer/ca-bundle` dependency.
- Added `platform_check.php` to enforce PHP version requirements.
- Created `initialize.php` for initializing the Mollie API client with the API key.
- Implemented `webhook_mollie.php` to handle webhook callbacks for software upgrade payments, including transaction status updates and invoice generation.
- Integrated DomPDF for generating invoices and sending them via email.

assets/mollie/src/Endpoints/ShipmentEndpoint.php

@@ -0,0 +1,145 @@
+<?php
+
+namespace Mollie\Api\Endpoints;
+
+use Mollie\Api\Exceptions\ApiException;
+use Mollie\Api\Resources\Order;
+use Mollie\Api\Resources\Shipment;
+use Mollie\Api\Resources\ShipmentCollection;
+class ShipmentEndpoint extends \Mollie\Api\Endpoints\CollectionEndpointAbstract
+{
+    protected $resourcePath = "orders_shipments";
+    /**
+     * @var string
+     */
+    public const RESOURCE_ID_PREFIX = 'shp_';
+    /**
+     * Get the object that is used by this API endpoint. Every API endpoint uses one type of object.
+     *
+     * @return Shipment
+     */
+    protected function getResourceObject()
+    {
+        return new \Mollie\Api\Resources\Shipment($this->client);
+    }
+    /**
+     * Get the collection object that is used by this API endpoint. Every API
+     * endpoint uses one type of collection object.
+     *
+     * @param int $count
+     * @param \stdClass $_links
+     *
+     * @return ShipmentCollection
+     */
+    protected function getResourceCollectionObject($count, $_links)
+    {
+        return new \Mollie\Api\Resources\ShipmentCollection($count, $_links);
+    }
+    /**
+     * Create a shipment for some order lines. You can provide an empty array for the
+     * "lines" option to include all unshipped lines for this order.
+     *
+     * @param Order $order
+     * @param array $options
+     * @param array $filters
+     *
+     * @return Shipment
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function createFor(\Mollie\Api\Resources\Order $order, array $options = [], array $filters = [])
+    {
+        return $this->createForId($order->id, $options, $filters);
+    }
+    /**
+     * Create a shipment for some order lines. You can provide an empty array for the
+     * "lines" option to include all unshipped lines for this order.
+     *
+     * @param string $orderId
+     * @param array $options
+     * @param array $filters
+     *
+     * @return Shipment
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function createForId($orderId, array $options = [], array $filters = [])
+    {
+        $this->parentId = $orderId;
+        return parent::rest_create($options, $filters);
+    }
+    /**
+     * Retrieve a single shipment and the order lines shipped by a shipment’s ID.
+     *
+     * @param Order $order
+     * @param string $shipmentId
+     * @param array $parameters
+     *
+     * @return Shipment
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function getFor(\Mollie\Api\Resources\Order $order, $shipmentId, array $parameters = [])
+    {
+        return $this->getForId($order->id, $shipmentId, $parameters);
+    }
+    /**
+     * Retrieve a single shipment and the order lines shipped by a shipment’s ID.
+     *
+     * @param string $orderId
+     * @param string $shipmentId
+     * @param array $parameters
+     *
+     * @return \Mollie\Api\Resources\Shipment
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function getForId($orderId, $shipmentId, array $parameters = [])
+    {
+        $this->parentId = $orderId;
+        return parent::rest_read($shipmentId, $parameters);
+    }
+    /**
+     * Update a specific Order Shipment resource.
+     *
+     * Will throw an ApiException if the shipment id is invalid or the resource cannot be found.
+     *
+     * @param string $shipmentId
+     * @param string $orderId
+     *
+     * @param array $data
+     * @return Shipment
+     * @throws ApiException
+     */
+    public function update($orderId, $shipmentId, array $data = [])
+    {
+        if (empty($shipmentId) || \strpos($shipmentId, self::RESOURCE_ID_PREFIX) !== 0) {
+            throw new \Mollie\Api\Exceptions\ApiException("Invalid subscription ID: '{$shipmentId}'. An subscription ID should start with '" . self::RESOURCE_ID_PREFIX . "'.");
+        }
+        $this->parentId = $orderId;
+        return parent::rest_update($shipmentId, $data);
+    }
+    /**
+     * Return all shipments for the Order provided.
+     *
+     * @param Order $order
+     * @param array $parameters
+     *
+     * @return ShipmentCollection
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function listFor(\Mollie\Api\Resources\Order $order, array $parameters = [])
+    {
+        return $this->listForId($order->id, $parameters);
+    }
+    /**
+     * Return all shipments for the provided Order id.
+     *
+     * @param string $orderId
+     * @param array $parameters
+     *
+     * @return \Mollie\Api\Resources\ShipmentCollection
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function listForId($orderId, array $parameters = [])
+    {
+        $this->parentId = $orderId;
+        return parent::rest_list(null, null, $parameters);
+    }
+}