[FrameworkBundle] Adds the possibility to register Commands via the DIC
feature #9199 [FrameworkBundle] Adds the possibility to register Commands via the DIC (fabpot)

This PR was squashed before being merged into the master branch (closes #9199).

Discussion
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[FrameworkBundle] Adds the possibility to register Commands via the DIC

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | don't now
| Fixed tickets | #8166
| License       | MIT
| Doc PR        | symfony/symfony-docs#3031

Todo:

* [x] Documentation
* [x] Clean code (add type hinting)
* [x] Add tests

Commits
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cabb1fa [FrameworkBundle] Adds the possibility to register Commands via the DIC
[FrameworkBundle] Added a command to open a controller from a path