getenv: Linux fix
cmake: fixed Linux C# unit tests
Overhauled how LibPKMN deals with strings

* Renamed pkmn::pokemon_text to pkmn::pkstring and propagated its usage
* SQLiteCpp: added function to return 16-bit strings from queries
* Python: added necessary typemaps+typechecks to use pkmn::pkstring
* Java: wrote wrapper functions to expose std::wstring instead of pkmn::pkstring
* Made unit tests more robust
swig: fix pkstring-related ignores