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/OrderEndpoint.php

@@ -0,0 +1,119 @@
+<?php
+
+namespace Mollie\Api\Endpoints;
+
+use Mollie\Api\Exceptions\ApiException;
+use Mollie\Api\Resources\Order;
+use Mollie\Api\Resources\OrderCollection;
+class OrderEndpoint extends \Mollie\Api\Endpoints\CollectionEndpointAbstract
+{
+    protected $resourcePath = "orders";
+    /**
+     * @var string
+     */
+    public const RESOURCE_ID_PREFIX = 'ord_';
+    /**
+     * Get the object that is used by this API endpoint. Every API endpoint uses one
+     * type of object.
+     *
+     * @return Order
+     */
+    protected function getResourceObject()
+    {
+        return new \Mollie\Api\Resources\Order($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 $_links
+     *
+     * @return OrderCollection
+     */
+    protected function getResourceCollectionObject($count, $_links)
+    {
+        return new \Mollie\Api\Resources\OrderCollection($this->client, $count, $_links);
+    }
+    /**
+     * Creates a order in Mollie.
+     *
+     * @param array $data An array containing details on the order.
+     * @param array $filters
+     *
+     * @return Order
+     * @throws ApiException
+     */
+    public function create(array $data = [], array $filters = [])
+    {
+        return $this->rest_create($data, $filters);
+    }
+    /**
+     * Update a specific Order resource
+     *
+     * Will throw a ApiException if the order id is invalid or the resource cannot be found.
+     *
+     * @param string $orderId
+     *
+     * @param array $data
+     * @return Order
+     * @throws ApiException
+     */
+    public function update($orderId, array $data = [])
+    {
+        if (empty($orderId) || \strpos($orderId, self::RESOURCE_ID_PREFIX) !== 0) {
+            throw new \Mollie\Api\Exceptions\ApiException("Invalid order ID: '{$orderId}'. An order ID should start with '" . self::RESOURCE_ID_PREFIX . "'.");
+        }
+        return parent::rest_update($orderId, $data);
+    }
+    /**
+     * Retrieve a single order from Mollie.
+     *
+     * Will throw a ApiException if the order id is invalid or the resource cannot
+     * be found.
+     *
+     * @param array $parameters
+     * @return Order
+     * @throws ApiException
+     */
+    public function get($orderId, array $parameters = [])
+    {
+        if (empty($orderId) || \strpos($orderId, self::RESOURCE_ID_PREFIX) !== 0) {
+            throw new \Mollie\Api\Exceptions\ApiException("Invalid order ID: '{$orderId}'. An order ID should start with '" . self::RESOURCE_ID_PREFIX . "'.");
+        }
+        return parent::rest_read($orderId, $parameters);
+    }
+    /**
+     * Cancel the given Order.
+     *
+     * If the order was partially shipped, the status will be "completed" instead of
+     * "canceled".
+     * Will throw a ApiException if the order id is invalid or the resource cannot
+     * be found.
+     * Returns the canceled order with HTTP status 200.
+     *
+     * @param string $orderId
+     *
+     * @param array $parameters
+     * @return Order
+     * @throws \Mollie\Api\Exceptions\ApiException
+     */
+    public function cancel($orderId, $parameters = [])
+    {
+        return $this->rest_delete($orderId, $parameters);
+    }
+    /**
+     * Retrieves a collection of Orders from Mollie.
+     *
+     * @param string $from The first order ID you want to include in your list.
+     * @param int $limit
+     * @param array $parameters
+     *
+     * @return OrderCollection
+     * @throws ApiException
+     */
+    public function page($from = null, $limit = null, array $parameters = [])
+    {
+        return $this->rest_list($from, $limit, $parameters);
+    }
+}