GraphQL: Optimize queries, fixes some null returns (on object), fix stitched GraphQLUpload (#6709)

* Optimize query, fixes some null returns, fix stitched GraphQLUpload

* Fix authData key selection

* Prefer Iso string since other GraphQL solutions use this format

* fix tests

Co-authored-by: Antonio Davi Macedo Coelho de Castro <adavimacedo@gmail.com>

src/Adapters/Storage/StorageAdapter.js

@@ -93,7 +93,7 @@ export interface StorageAdapter {
     fieldNames: string[],
     indexName?: string,
     caseSensitive?: boolean,
-    options?: Object,
+    options?: Object
   ): Promise<any>;
   ensureUniqueness(
     className: string,