Migrate cache to Apollo v3 about vulcan

[ErikDakoda]

I am seeing a lot of "Invariant Violation" errors from Apollo 3 in the browser console. They are not causing breaking errors, but they are an indication that the Apollo client cache is probably not operating efficiently.

So the point is that we need to move on this sooner rather than later.

In addition, there are other vestiges of Apollo 2 like apollo-link-state that we should probably deprecate from the Vulcan code (see apollographql/apollo-client#5982). In this case it's possible that nobody in Vulcan land is using link state - but how do we find that out? Is it safe to just remove this feature?

I could probably make these changes, but I can't commit to starting right away because of other deadlines I have. But if I do start on this, how do I make sure that no-one else is doing the same work? To discuss that question further, I will open another issue.

[eric-burel]

Contribution on Apollo v3 would be muuuch appreciated. If you start something, I would simply suggest releasing a patch version of Vulcan current code before we merge the work, and then release a minor.

It's ok to have breaking change, as long as we rely on semantic versioning. There is also a MIGRATING.md where you can explain breaking changes manually + the automated changelog.