ipapwpolicy: Fix documentation sections and agument spec

ansible-test with ansible-2.14 is adding a lot of new tests to ensure
that the documentation section and the agument spec is complete. Needed
changes:

DOCUMENTATION section

- `type: str` needs to be set for string parameters
- `type: list` needs to be set for list parameters
- `elements: str` needs to be given for list of string parameters
- `author` needs to be given with the github user also: `Name (@user)`
- `extends_documentation_fragment: ipamodule_base_docs` needs added and
  `ipaadmin_*` parameters need to be removed

argument_spec

- `elements="str"` needs to be added to all list of string parameters

The `copyright` date is extended with `-2022`.