Allow Symfony 8

Merge remote-tracking branch 'origin/2.x' into 2.x

Add CommandInterface & deprecate passing a command not implementing it

Allow Symfony 7 (#8)

* Allow Symfony 7
* Move PHP CS Fixer & PHPStan to separate composer.json files
* Install dev packages for some unreleased Symfony versions
* Add Changelog entry

Update changelog for v1.1.0

Add badges on README