Move graph layout calculation to frontend

[VictorKuenstler]

Possible relevant use cases:

• Users could have full control over graph layout configurations
• Grouping nodes into separate (sub-)pipelines could be done using combo groups of G6
• Grouping/filtering nodes can be achieved while providing a useful graph layout
• Updates (new nodes e.g., connectors, streams apps, topics, ...) could be handled without a whole graph reload
• E.g., in the future, Kafka streams app nodes could be expanded to display internal topologies as part of the whole data pipeline

[disrupted]

I have been testing it.

• For now the calculated Graph layout from G6 (using Dagre algorithm) looks less robust and structured than what Graphviz currently provides. Perhaps we could re-visit this in a future update of G6.
• Combo groups unfortunately don't seem to have an effect on de-cluttering the graph with multiple connected pipelines.

Will be putting this on hold for now.