Update 'next-3.x' with latest changes from 'main'

See merge request !19

fix: improve PayPal popup handling

See merge request !20

This commit adds some necessary class existence checks in various order processing scripts. The
checks are performed to ensure the presence of 'QUI\\ERP\\Order\\Handler' and
'QUI\\ERP\\Order\\Basket\\Basket' classes. If these classes are missing, the functions return
either an empty array with specific keys or false. This change aims to prevent errors during order
processing due to missing classes.

Adjustments made to PaymentDisplay.css and PaymentDisplay.js improve user interface for recurring
payments. Specifically:

- Button appearance adjusted with new border radius, alignment changes.
- Included an img tag with side and margin properties.
- Made changes to buttonText and content classes.
- Added function to handle PayPal payment success and error.
- Included additional images for Paypal-Logo and Paypal.
- Added text under the button using an additional div.
- Updated locale XML with a new error message during the payment process.

This commit includes modifications in `PaymentDisplay.css` and `PaymentDisplay.js` related to the
PayPal recurring payment display.

In `PaymentDisplay.css`:
- Customizing the PayPal button hover effect using CSS.
- Changing button properties for a better responsive design.

In `PaymentDisplay.js`:
- Updating deprecated var declarations to const and converting to arrow function for clean and
efficient code.
- Adding better error handling for failed PayPal window opening.
- Reformatting existing event listeners and function calls for code readability.

Updating the locale.xml to include error messages related to pop-up blocking in both German and
English.

feat: improved PayPal recurring payment confirmation

See merge request !18

Detailed changes:
- Enhanced error handling in PaymentDisplay.js (reduced risk of uncaught exceptions)
- Formatted recurringReturn.php and removed a commented-out debugging statement
- Trimmed extra query character from return_url in BillingAgreements.php
- Added orderHash to return URL in Payment.php

This commit changes the method of selecting the orderProcessNode in the PaymentDisplay.js file. The
`getElm().getParent( ... )` method is replaced with `document.querySelector( ... )` which provides
more accurate and consistent results.

This commit applies consistent formatting to type hints throughout the codebase. Specifically, it
ensures that there is a space either side of the pipe (|) character in union type hints, consistent
with formatting guidelines.

Changes were made to methods in the `BillingAgreements` and `Payment` classes in the following
files:
- src/QUI/ERP/Payments/PayPal/Recurring/BillingAgreements.php
- src/QUI/ERP/Payments/PayPal/Recurring/Payment.php

Changes made across multiple files involving the recurring payment flow for PayPal.
- Added eventListener for successful payment message in PaymentDisplay.js.
- Updated the redirect logic in recurring/Payment.php to point to the recurring return PHP script.
- Hidden the request dump in recurringReturn.php and replaced with a cleaner page title and a
script to handle window opening events.
- The BillingAgreements script gets URL for return directly from the host rather than using Gateway
method calls.
- Applied various minor code styling corrections.
- Payment as Popup

fix: return type

See merge request !17

Next 2.x

See merge request !16

Next 2.x

See merge request !15

fix: requirement - master to main

See merge request !13

feat!: quiqqer v2

See merge request !11

feat!: quiqqer v2

See merge request !10

feat!: quiqqer v2

See merge request !9