Changes

tsk81 Updates method to get favorites filtered by title
The REST method to get the favorites of a user has been modified in
order to be able to filter them by the title. The filter is applied on
the favourite list of the AuthorEntity, instead of querying the
database. In addition, a test for this method has been added to check if
the filter works as expected. For this, a favorite list of the logged in
user was added to the StoryDataset.