feature request: Group kedro nodes in same DAG task

[sbrugman]

The documentation reads:

Every kedro node is transformed into Airflow DAG task.

As software engineers, we may want to have multiple kedro nodes correspond to a single DAG task when logical separation of code in multiple nodes is preferred (e.g. for readability or reuse). This would also allow datasets of type "MemoryDataset", that would need grouping by default.

For this kedro-airflow-k8s could detect groups of nodes similar to spark grouping.