[Translation] added LoggableTranslator.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #3015, #2435
| License       | MIT
Why use non-usual way? Let's do on same manner like in Swiftmailer/Doctrine other bundles and how documentation suggests (provide argument `$debug` for the configuration class.