Simplify and update train type translations (#213)

* Simplify and update train type translations

Updated train types for EN/PL according to Annex 6.3 of the 2024/2025 Network Statement. Description of the ZX type is taken from Annex 6.1 of the 2018/2019 Network Statement, which was the last version containing it.

* rewiew changes

Author: AMelonInsideLemon