Improve readability and interpretability of code by explicitly stating null in union types. This
change has been applied across multiple files and functions.

PHP8.4 compatibility

Related: order-guestorder#6

Related: order-guestorder#6

Related: quiqqer/order#163

The UX was not optimal as a result. It was not clear that you could scroll and the guest order button was not visible.
For now flex removed and the login buttons are below each other

Related: template-cologne#111

(cherry picked from commit 065225a2)

Co-authored-by: Michael Danielczok <michael@pcsg.de>