Add InPost Pay integration to admin templates

- Created a new template for the cart rule form with custom label, switch, and choice widgets.
- Implemented the InPost Pay block in the order details template for displaying delivery method, APM, and VAT invoice request.
- Added legacy support for the order details template to maintain compatibility with older PrestaShop versions.

modules/inpostizi/vendor/psr/http-message/README.md

@@ -0,0 +1,13 @@
+PSR Http Message
+================
+
+This repository holds all interfaces/classes/traits related to
+[PSR-7](http://www.php-fig.org/psr/psr-7/).
+
+Note that this is not a HTTP message implementation of its own. It is merely an
+interface that describes a HTTP message. See the specification for more details.
+
+Usage
+-----
+
+We'll certainly need some stuff in here.