[NEW] Clear au moment du START serveur

[bfoujols]

Afin d'améliorer la visibilité, la commande clear pourra permettre de voir les informations importantes

#console Output Sections

        $section1 = $output->section();
        $section2 = $output->section();

        $section1->writeln('Hello');
        $section2->writeln('World!');
        sleep(1);
        // Output displays "Hello\nWorld!\n"

        // overwrite() replaces all the existing section contents with the given content
        $section1->overwrite('Goodbye');
        sleep(1);
        // Output now displays "Goodbye\nWorld!\n"

        // clear() deletes all the section contents...
        $section2->clear();