EZP-20426 - Legacy cronjobs and scripts should be launchable from Symfony CLI

**Work in progress. DO NOT MERGE**

## Description
It's currently impossible to launch legacy cronjobs/scripts from Symfony context (`ezpublish/console`), which is a blocker is many cases (like HTTP cache clear operations during cronjobs execution).

One should be able to run a command like :
```bash
php ezpublish/console ezpublish:legacy:cronjobs frequent
php ezpublish/console ezpublish:legacy:script bin/php/ezpgenerateautoloads.php
```

## Tasks
* [x] Adapt `CLIHandler` to be able to use `run()` method
* [x] Create a console command to run legacy scripts
* [ ] Make it possible to use short options with legacy scripts
* [ ] (*optional*) Create a dedicated command for cronjobs