[ACA-3358] Show user friendly error templates when there are no applications/processDefinitions (#5746)

* * Added empty template on start process component

* * Removed errorMessageId

* * Added unit tests to recent changes

* * Added doc

* * fixed comments

* * Used showError notification

* * After rebase

* * Fixed failing e2e

* * Fixed comments

docs/process-services/components/start-process.component.md

@@ -195,6 +195,25 @@ You can use the `showSelectApplicationDropdown` property to Hide or show applica
 ![Start process with selected application](../../docassets/images/start-process-with-selected-application.png)
 
 
+### Error handling
+
+When an error occurs, the component will emit an error event that can be used to handle errors. Example:
+
+```html
+ <adf-start-process 
+      [appId]="YOUR_APP_ID"
+      [title]="'ADF_PROCESS_LIST.START_PROCESS.FORM.TITLE'"
+      [name]="PROCESS_NAME"
+      (error)="onError($event)">
+ </adf-start-process>		 
+```
+
+```ts
+    onError(error) {
+        this.notificationService.showError(event.response.body.message);
+    }
+```
+
 ## See also
 
 -   [Select Apps Dialog component](select-apps-dialog.component.md)