[ADF-4731] [Process - Cloud] - Improve IdentityUserService (#4924)

* [ADF-4731][Process - Cloud] - Improve IdentityUserService.

* * Updated unit tests.

* * Updated IdentityUserService document
* Fixed comments on the pr.

* * Added missing 'createdTimestamp' property to the IdentityUserModel.

* * Created IdentityJoinGroupRequestModel. * Updated doc. * Updated unit tests.

lib/core/userinfo/models/identity-group.model.ts

@@ -0,0 +1,38 @@
+/*!
+ * @license
+ * Copyright 2019 Alfresco Software, 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.
+ */
+export class IdentityGroupModel {
+
+    id: string;
+    name: string;
+    path: string;
+    realmRoles: string[];
+    clientRoles: any;
+    access: any;
+    attributes: any;
+
+    constructor(obj?: any) {
+        if (obj) {
+            this.id = obj.id || null;
+            this.name = obj.name || null;
+            this.path = obj.path || null;
+            this.realmRoles = obj.realmRoles || null;
+            this.clientRoles = obj.clientRoles || null;
+            this.access = obj.access || null;
+            this.attributes = obj.attributes || null;
+        }
+    }
+}