Add tests related to error handling.

Traditional British long count is available for systems.

Make short millia parse and stringify correctly.

Add namespace for short/long count. Also manage conversion configs and defaults.

Ensure exponents are normalized properly.

Use bigint for place values to be more adaptable with longer inputs.

Make group management more readable.

Address errors with gapped groups.

Make code more cleaner when parsing.

Include parse and stringify functions for American short-count locale.