Allow Updates to Output Parameters of in-progress Tasks via Plugin API #373
Description
We should allow updates to Task resources with status in-progress. Updating in-progress Task resources should be supported by the Plugin API to make sure the Task resource available via the Variables interface reflect the modifications.
The TaskAuthorizationRule should allow updates from in-progress to in-progress for adding, modifying or removing output parameters.
The documentation should instruct developers not to use this feature as a method of communicating intermediate process states to external organizations. This feature is intend to simplify local debugging and for example to store the URLs of QuestionnaireResponse resources associated with the running process. Communicating intermediate states to external organizations should always be explicitly modeled in the process via intermediate message throw and catch events.