Log missing fields with queries

If a cache update causes a field to go missing, usually do to merging non-normalized data, this can cause refetches of other queries. It would be helpful if we could indicate in some way what fields went missing during a cache write.

No file, test, or entry point is named. Start by locating cache-write handling and the path that refetches queries after fields go missing, then review how non-normalized data is merged. Done means the devtools can indicate which fields disappeared during a cache write.

Written by the indexing model from the issue text.