##### SUMMARY
`esc_period` is mandatory even with `state: absent` - should be optional in that case.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
zabbix_action

##### ANSIBLE VERSION
latest

##### CONFIGURATION
Not relevant.

##### OS / ENVIRONMENT
Not relevant.

##### STEPS TO REPRODUCE
```yaml
  - name: "Report problems to Zabbix administrators"
    event_source: 'trigger'
    state: absent
```

##### EXPECTED RESULTS
Action, if exists, is removed.

##### ACTUAL RESULTS
```paste below
"msg": "missing required arguments: esc_period"
```
- Defaults to C(custom_expression) when formula is specified.
        choices:
            - 'andor'
            - 'and'
            - 'or'
            - 'custom_expression'
    formula:
        description:
            - User-defined expression to be used for evaluating conditions of filters with a custom expression.
            - The expression must contain IDs that reference specific filter conditions by its formulaid.
            - The IDs used in the expression must exactly match the ones
              defined in the filter conditions. No condition can remain unused or omitted.
            - Required for custom expression filters.
            - Use sequential IDs that start at "A". If non-sequential IDs are used, Zabbix re-indexes them.
              This makes each module run notice the difference in IDs and update the action.
    default_message:
        description:
            - Problem message default text.
    default_subject:
        description:
            - Problem message default subject.
    recovery_default_message:
        description:
            - Recovery message text.
            - Works only with >= Zabbix 3.2
    recovery_default_subject:
        description:
            - Recovery message subject.
            - Works only with >= Zabbix 3.2
    acknowledge_default_message: