Stub out GraphQL story cards

[marcello-silverstripe]

AC:

• Ready for (remaining) implementation to be sized by open sourcerers

[chillu]

Closing this even in favour of more focused research cards: silverstripe/silverstripe-graphql#11 and silverstripe/silverstripe-graphql#10. Turns out to be more investigation work than the three points assigned here, between Will and myself we've spent that amount of time already just identifying what to research.