Started generate_enums.py, which will generate enum files for all languages

* Currently grabs most relevant values from database
generate_enums: most un-nested namespaces format correctly
generate_enums: get forms
Nested formatting works, actual forms not yet
C++ form enum properly generated, no filtering to proper names yet
Form name filtering
First placement of generated enums.hpp, no compile test yet
Work on C++ compiling
C++ library compiles
tests: replaced LIBPKMN_DATABASE_DIR with LIBPKMN_DATABASE_PATH, Linux works
generate_enums.py creates Python files for enums
Fixed LibPKMN __init__.py
Fixed Python import
Non-nested C# enums generated as C# static classes, adjusted C# Doxygen docs to include them
All C# static classes generated
All non-nested enums converted to Java classes
All enums install
Work on incorporating enum changes into base_pokemon_modernimpl
base_pokemon_modernimpl: set_form w/number parameter done
Propagated new form enums into base_pokemon_modernimpl