fix(graphcache): Fix typo in owned data null resolution for resolvers

[kitten]

Resolves #3370

Summary

This fixes a typo in an inverted condition for an owned data check in resolveResolverResult. The equivalent check in resolveLink is isOwnedData && prevData === null, i.e. when a prior result was null it keeps the field set to null.

Instead, the resolver did the opposite and hence turned a first resolution of a prevData === null result into a nulled value, i.e. preventing subsequent results from succeeding.

Set of changes

• Fix inverted resolveResolverResult condition for owned null values