New Features:
- Add Employer Identification Number (EIN) validator (#163)
- Add International Standard Recording Code (ISRC) validator
- Add Global Release Identifier (GRid) validator (#164)
- Add Danish CPR (Det Centrale Personregister) validator (#170)

Bug Fixes:
- Fix IBAN validation crashes on invalid characters (#180)

Improvements:
- Refactor: Convert assignment statements to usage of combined operators (#174)