Refactor lineage view to use graph service

[ableuler]

MVP

• Query the lineage API of the gateway rather than the artefacts API. (Needs the first two sub-issues of Provide API for lineage queries renku-gateway#71 to be resolved).
  Done in UI for configuring KG integration #374 and Use graph services for lineage display #392

post - MVP

Improve presentation and interactivity by making projects expandable on click.

[rokroskar]

@ciyer the necessary pieces are in place for this to be done. It seems to me that the changes required for the first item are pretty minimal -- could you have a look?

[rokroskar]

closing this otherwise it could stay open indefinitely -- @ciyer @lorenzo-cavazzi could you please make another issue to address the post-MVP part?

[lorenzo-cavazzi]

I think the "on click" interactivity is already covered by #256 . Not sure if the second point here was in the same direction, but with #400 it will be also easy to preview project files.