[FrameworkBundle] Improved controller class error

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | https://github.com/symfony/symfony/issues/11304
| License       | MIT
| Doc PR        | 
@stof I'm going to call on you - what do you think about @guilhermeblanco's approach here and the approach in the issue? I want to bump this along, so I'd love your opinion.