feat(graphcache): track types in the data-structure

Related to #3470

Summary

This starts tracking a mapping of __typename to a list of entityKey, this enables us to perform operations like invalidate('Todo') which would invalidate every entityKey of the Todo type.

We add non-root typenames when going through the write operation and we clean up entities in the list when we are going through gc runs.

In the future this can instruct us for operations where we can't derive an entity i.e. a create-mutation will invalidate all entities of its own type to ensure we don't run into stale values which leaves us with the scalar return case which won't automatically be handled.

The PR explicitly does not add the updater logic yet so we can see that the explicit API surface does not grow, we support more cases instead.

Set of changes

Add Map of __typename to a list of keys
Add support for invalidate('Type') and inavlidate({ __typename: 'Type' })

Questions

Should we support invalidating a full type with field and arguments i.e. invalidate('Todo', 'author') would go through every Todo key and explicitly invalidate the Author field.

Follow-ups

After this PR we can provide logic where we check the presence of the entity in cahce when there's no updater. When we can't find the entity we perform invalidate({__typename})

urql-graphql / urql