MOBILE-4059 core: Improve CoreObject types

Type helper extracted from https://stackoverflow.com/questions/57571664/typescript-type-for-an-object-with-only-one-key-no-union-type-allowed-as-a-key/57576688#57576688

src/core/singletons/object.ts

@@ -12,13 +12,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-export type CoreObjectWithoutEmpty<T> = {
-    [k in keyof T]: T[k] extends undefined | null ? never : T[k];
-};
+import { Pretty } from '@/core/utils/types';
 
-export type CoreObjectWithoutUndefined<T> = {
-    [k in keyof T]: T[k] extends undefined ? never : T[k];
-};
+type ValueWithoutEmpty<T> = T extends null | undefined ? never : T;
+type ValueWithoutUndefined<T> = T extends undefined ? never : T;
+
+export type CoreObjectWithoutEmpty<T> = Pretty<{
+    [k in keyof T]: ValueWithoutEmpty<T[k]>;
+}>;
+
+export type CoreObjectWithoutUndefined<T> = Pretty<{
+    [k in keyof T]: ValueWithoutUndefined<T[k]>;
+}>;
 
 /**
  * Singleton with helper functions for objects.

src/core/utils/types.d.ts

@@ -0,0 +1,18 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * Helper type to flatten complex types.
+ */
+export type Pretty<T> = T extends infer U ? {[K in keyof U]: U[K]} : never;