refactor(contact_player.py): part2: improve type hints, add docstrings

[axodentally]

See commits:

refactor(contact_player.py): improve type hints, add docstrings

refactor(contact_player.py): simplify code

refactor(ccp.py): improve typing

refactor(contact_player.py): use explicit import

[axodentally]

This change is part of the following stack:

• refactor(contact_player.py): part1: basic refactoring, move functionality to main() function #20
  • refactor(contact_player.py): part2: improve type hints, add docstrings #21 ◀
    • refactor(contact_player.py): part3: Introduction of a new data model and addition of some level of abstraction #22
      • feat(contact_player): initial planned_contacts support #23
        • tests: add unittests #24
          • Introduce pyproject.toml, restructure installation #25

_{Change managed by git-spice.}