Be able to edit timeout event on task listeners

Is your feature request related to a problem? Please describe.

Starting with Camunda BPM Runtime 7.12.0-alpha4, time-triggered task listeners can be used.

An example looks like this:

...
<bpmn:userTask id="myTask">
  <bpmn:extensionElements>
    <camunda:taskListener delegateExpression="${setBusinessKeyListener}" event="timeout" id="timeout-friendly" >
      <bpmn:timerEventDefinition>
        <bpmn:timeDuration xsi:type="bpmn:tFormalExpression">PT1H</bpmn:timeDuration>
      </bpmn:timerEventDefinition>
    </camunda:taskListener>
  </bpmn:extensionElements>
</bpmn:userTask>
...

Expected solution

1. Value timeout allowed for event attribute of camunda:taskListener
2. Element timerEventDefinition now allowed as a child of camunda:taskListener, but only if the event of the camunda:taskListener is set to timeout
3. New attribute id for camunda:taskListener, only mandatory if event of camunda:taskListener is set to timeout

• Existing property panel controls for TimerBoundaryEvents can be used here as well for the timer event definition, if the timeout value is chosen as event type of the task listener.

Additional context

Should be shipped with Camunda Modeler until 30th of November, as it is supported in the upcoming Camunda Platform 7.12 release.

Original opened issue: https://github.com/camunda/camunda-bpmn-moddle/issues/50.

[nikku]

Let’s restrict the UI side for now. Reasoning:

• The engine validates anyway
• Validation is super complex on the moddle side for this one

[pinussilvestrus]

Waiting for upstream changes to be released, cf. https://github.com/bpmn-io/bpmn-js-properties-panel/pull/321