[Open Task] Replace storyboard for `LanguageScreenViewController` with code.

## **GOAL**
`LanguageViewController`'s storyboard reference should be replaced with code. The view controller should be instantiated without the need of a storyboard.

## **WHY**
Storyboards are hard to maintain.

## **ACCEPTANCE CRITERIA**

- Replace storyboard related stuff of `LanguageViewController` with code.
- Remove associated scene in `Main.storyboard`
