Refactor modules and tests #minor

[cobaltine]

Module structure:

• Detached jfpv1 logic into a separate _jfpv1 module
• Detached basic validators into a separate _validators module

Tests:

• Simplified test runner execution with test module loading via
  the parent init.py
• Extended and clarified docstrings for several tests
• Split existing and new tests into a per-module type structure
• Added more detailed tests (positive-negative testing) for exceptions
• Extended 'manual' jfpv1 testing, from raw flattened json output to
  actual fingerprint

CI:

• Updated test runner execution