fix(graphcache): backport invalidation fix (#3545)

.changeset/ninety-taxis-return.md

···
+---
+'@urql/exchange-graphcache': patch
+---
+
+Fix `invalidate` not applying when using a string to invalidate an entity

exchanges/graphcache/src/store/store.test.ts

···
   });
 
   describe('Invalidating an entity', () => {
-    it('removes an entity from a list.', () => {
+    it('removes an entity from a list by object-key.', () => {
       InMemoryData.initDataState('write', store.data, null);
       store.invalidate(todosData.todos[1]);
+      const { data } = query(store, { query: Todos });
+      expect(data).toBe(null);
+    });
+
+    it('removes an entity from a list by string-key.', () => {
+      InMemoryData.initDataState('write', store.data, null);
+      store.invalidate(store.keyOfEntity(todosData.todos[1]));
       const { data } = query(store, { query: Todos });
       expect(data).toBe(null);
     });

exchanges/graphcache/src/store/store.ts

···
   invalidate(entity: Entity, field?: string, args?: FieldArgs) {
     const entityKey = this.keyOfEntity(entity);
     const shouldInvalidateType =
-      entity && typeof entity === 'string' && !field && !args;
+      entity &&
+      typeof entity === 'string' &&
+      !field &&
+      !args &&
+      !this.resolve(entity, '__typename');
 
     if (shouldInvalidateType) {
       invalidateType(entity);