Refactor/dexutils

[Denmark14]

Resolves #27

• Utils are to be extracted from the mega script and cleanly added to their own individual files.
• Added index for easier importing.
• Utils themselves will be updated as improvements were made in other projects that were not backported to this repo.
• Imports will be updated in other files where needed.
• Attempts will be made to reduce the impact on existing code, but some behavioral changes are necessary to reduce bugs and unnecessary computations.

Todo:

• [x] Create unit tests for utils
• [x] Update imports in necessary files
• [x] Test functionality of the Pokedex