Add compatibility with Symfony 7 and 8, rework service config to PHP

Fix nullable typing causing a deprecation in PHP 8.4

Remove spaceless filter usage

Merge pull request #86 from symfony2admingenerator/fix-deprecation

Fix wrong reference and fix deprecation in return type

Move to Font Awesome 6 icons

Fix Vich uploader reference

Directly reference the uploader helper instead of the extension, fixing issues with the newer Vich uploader versions that use feature the lazy Twig extension.

Fix return type in Twig extension

Fix possible issue with getting the Session before it has been populated

Add missed return type in MoneyType

Fix deprecations, update to PHP 8.1 and supported deprecations versions