ansible_freeipa_module: Use ipaplatform.tasks.parse_ipa_version

api_check_ipa_version was using packaging.version. IPA is using
pkg_resources.parse_version in ipaplatform.tasks.parse_ipa_version.

With this change tasks.parse_ipa_version from ipaplatform is used to
have exactly the same version comparison that also IPA has.

Additionally tasks is added to __all__.