[ADF-3938] support for XMLHttpRequest.withCredentials flag (#4190)

* support XMLHttpRequest.withCredentials

* proper defaults and json schema updates

* remove outdated docs

* remove empty declaration from app config

* fix blob support

docs/core/app-config.service.md

@@ -66,22 +66,6 @@ Example of the default settings file content:
 Note that the settings in the example above are the default ones supplied with the server.
 You can override the values in your custom `app.config.json` file if necessary. 
 
-You can change the path or name of the configuration file when importing the [`CoreModule`](../../lib/core/core.module.ts) in your main application.
-
-```ts
-...
-@NgModule({
-    imports: [
-        ...
-        CoreModule.forRoot({
-            appConfigFile: 'app.production.config.json'
-        })
-    ],
-    ...
-}
-export class AppModule { }
-```
-
 Below is a simple example of using the [`AppConfigService`](../core/app-config.service.md) in practice. 
 
 **[app.component](../../demo-shell/src/app/app.component.ts).ts**
@@ -156,3 +140,16 @@ of a property when the app config is loaded:
         console.log(logLevelValue); //this will be 'trace';
     });
 ```
+
+## XMLHttpRequest.withCredentials
+
+In the configuration file, you can enable [XMLHttpRequest.withCredentials](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/withCredentials)
+for @alfresco/js-api calls and PDF Viewer.
+
+```json
+{
+    "auth": {
+      "withCredentials": true
+    }
+}
+```