No error or alert is displayed if the user tries to add already existing document to collections or favorites

[Souvik_]

1. Login to Nuxeo.
2. Navigate to Personal Workspace 3.Select checkbox provided with a document which is already added as favorites. 4.Alternatively navigate to favorites and click on "+" icon to add documents to favorites 5.Type name of already existing document , select from suggestions and click on "add to collections" button

Expected Result: An error or alert message should be displayed if an already existing document is being added again and the document should not get added

Actual Result: No error or alert message is displayed if an already existing document is being added again, the document however does not gets added to collections/favorites