Done:
* Replace LanguageConverter::newConverter by LanguageConverterFactory::getLanguageConverter
* Remove LanguageConverter::newConverter from all subclasses
* Add LanguageConverterFactory integration tests which covers all languages by their code.
* Caching of LanguageConverters in factory
* Make all tests running (hope that's would be enough)
* Uncomment the deprecated functions.
* Rename FakeConverter to TrivialLanguageConverter
* Create ILanguageConverter to have shared ancestor
* Make the LanguageConverter class abstract.
* Create table with mapping between lang code and converter instead of using name convention
* ILanguageConverter @internal
* Clean up code
Change-Id: I0e4d77de0f44e18c19956a1ffd69d30e63cf51bf
Bug: T226833, T243332
