When Configuration/Datastore class is empty it is displayed in Studio as a Text field

expected: no field at all
actual: Text field is shown

Steps to reproduce:
1. clone repository and build following component https://github.com/Talend/component-runtime-qa/tree/master/components/qa
2. deploy component to Studio using following command mvn package talend-component:deploy-in-studio -Dtalend.component.studioHome=/path/to/studio
3. Start Studio, add QAQASuggestions component on design palette.
4. Open component properties. You'll see text field with "dataStore" label. However, datastore class has no property fields
https://github.com/Talend/component-runtime-qa/blob/master/components/qa/src/main/java/org/talend/components/qa/actions/suggestable/QASuggestionsDatastore.java
In case of empty Dataset or Datastore classes Studio should not create a property field for them.