[WIPTEST] Types fixes

[jarovo]

Enhancement the types in the project, allowing the pyCharm and other editors do better job of types-based hinting and perhaps mypy compliance in the end

[dajoRH]

I detected some fixture changes in commit e8874ffd335e81129cadcbe7599af823500b1106

The local fixture datastore is used in the following files:

• cfme/tests/infrastructure/test_datastore_analysis.py
  • datastores_hosts_setup
  • test_run_datastore_analysis

The local fixture datastores_hosts_setup is used in the following files:

• cfme/tests/infrastructure/test_datastore_analysis.py

Please, consider creating a PRT run to make sure your fixture changes do not break existing usage 😃