Feature: Implement Idempotency

[oelu]

Currently it is possible to run modules with add, edit, get, or delete actions.
It would be nice if the modules would support idempotent actions with states state=present or state=absent. This would help to reduce code complexity in in playbooks.

From the Ansible glossary (https://docs.ansible.com/ansible/latest/reference_appendices/glossary.html):
Idempotency
An operation is idempotent if the result of performing it once is exactly the same as the result of performing it repeatedly without any intervening actions.