#### Story
When I use deprecated functions related to LanguageConverter in the Language class,
I want to use global access to LanguageConverterFactory via MediawikiServices::getInstance(),
to avoid unwanted cycle dependency between `Language` and `LanguageConverterFactory`.
#### Context
At the moment Language::getConverter provides access to the converter using LanguageConverterFacory injected by DI.
```lang=php
public function getConverter() : ILanguageConverter {
return $this->converterFactory->getLanguageConverter( $this );
}
```
#### Expected Result
* access to factory should be implemented via MediawikiServices::getInstance()->getLanguageConverterFactory
* converterFactory should be removed
* cyclic dependency should be avoided
* LanguageConverterFactory should access $defaultLanguage as value, not closure