PokemonApi, Pokemon, TypeRealtion - Milestone 2

This MR is for the reconstruction of Pokémon, PokémonAPI and Type Relations for milestone 2.
They now are fully organized and fully functional. Hence Pokémon creation should not be a problem anymore. Nor is the slow creation of the pokemon.
Keep note that there is a bug in the simplifer.kt file which is waiting for a fix from the teacher.