Graph format: Refactor Graph format

[gesinn-it-gea]

Issue

Following up on PR #297 . New attempt to refactor the Graph format based on current SRF code base and smaller PRs.

• separate "Graph" format from "Graphviz" (create own format in src/Graph)
• follow the notes in Move vCard to SRF\vCard #314 and Moving from /formats to /src #321
• reuse pieces from Graph format: Refactoring and enhancing #297

gesinn.it team will work on this

[kghbln]

@gesinn-it @RacoonDev With the current implementation there is an issue for the "graph" format when using special page "Ask". See the note at this spot. It will be cool if you will have a peep at this too while doing cools stuff here. :) Thanks and cheers.

[krabina]

What is the status of this?
The GraphViz extension has been archived, because it has stopped working since MW 1.33. This means that both formats graph anc process are no longer working.
Would they work with the maintained extension "Diagrams"?

[krabina]

oh, see #803
But how can it "fix Extension GraphViz support, if the extension itself is no longer working?

[JeroenDeDauw]

When #803 is merged, graph format works again with GraphViz.

[JeroenDeDauw]

@krabina this is on an older version of MediaWiki. You are probably right about never versions