Add X13 WebP module for image conversion to next-generation formats

- Implemented the X13Webp class with core functionalities for converting images to WebP format.
- Added support for different PHP versions and defined constants for versioning.
- Included translation strings for various user interface elements and messages.
- Created XML file for module versioning.

modules/x13webp/vendor/rosell-dk/exec-with-fallback/test.php

@@ -0,0 +1,9 @@
+<?php
+include 'vendor/autoload.php';
+//include 'src/ExecWithFallback.php';
+use ExecWithFallback\ExecWithFallback;
+use ExecWithFallback\Tests\ExecWithFallbackTest;
+
+ExecWithFallback::exec('echo hello');
+
+ExecWithFallbackTest::testExec();