EPIC: migrate solvis-graphql-api features

[chrisbc]

some features were developed in solvis-graphql-api can made be more widely available and more generalised in solvis

Considering:

• site-rupture radius calculations (runtime vs stored)
• do we want a separate library for visualisation features (e.g. color scales),

Done when:

• feature: migrate rupture rate filtered functions from solvis-graphql-api #37
  • fault and rupture distance filtering
  • parent fault filtering
  • Epic Feature: enhanced participation rate options #42

Future Candidates:

• get fault surfaces geojson
• get fault traces geojson
• geojson styling helpers
• color scale