Find alternative to vis.js

[Cypher1]

Current state

Vis.js (https://github.com/mdaines/viz.js) is no longer maintained or supported.
It may be necessary to find a replacement in future.

Future work

• Look at possible replacements and their trade offs
• Test a chosen replacement and integrate with it

Possible alternatives:

• https://github.com/CyberhavenInc/graphviz-wasm
• https://github.com/erikbrinkman/d3-dag
• https://github.com/dagrejs/dagre

[Cypher1]

vis.js is added in #56

[Cypher1]

Done in #86 ! We're now using d3-graphviz with a plan to move to native d3 soon