Api 7.3 InputPollOption

[Bibo-Joshi]

Checklist

• Added .. versionadded:: NEXT.VERSION, .. versionchanged:: NEXT.VERSION or .. deprecated:: NEXT.VERSION to the docstrings for user facing changes (for methods/class descriptions, arguments and attributes)
• Created new or adapted existing unit tests
• Documented code changes according to the CSI standard <https://standards.mousepawmedia.com/en/stable/csi.html>__
• [] Added myself alphabetically to AUTHORS.rst (optional)
• Added new classes & modules to the docs and all suitable __all__ s
• Checked the Stability Policy <https://docs.python-telegram-bot.org/stability_policy.html>_ in case of deprecations or changes to documented behavior

If the PR contains API changes (otherwise, you can ignore this passage)

• Checked the Bot API specific sections of the Stability Policy

• New classes:

  • Added self._id_attrs and corresponding documentation
  • __init__ accepts api_kwargs as kw-only