[DX] Adding a CI

[Kocal]

When opening a PR, there is no CI that ensure the code follows some code-style, and run tests for different version of Symfony (with lowest or higher deps).

The idea is to re-implement (partially or fully) the work done in https://github.com/Kocal/ckfinder-symfony-bundle/blob/main/.github/workflows/continuous-integration.yaml.

Which renders the following checks: