Child flow node instances should be requested dynamically, when clicking the expand button of a parent instance.
- When clicking the expand button: Request the API with pageSize 50 to load the first 50 child instances.
- When clicking the collapse button: All flow node instances should be removed from the store
- When clicking the expand button only the direct children will be loaded. In case there is a deeper nesting, we show expand buttons on the child instances
- When collapsing a parent instance, all child instances (including potential nested ones) should be removed from the store