Allow calling a recommender for the current view

[reckart]

Is your feature request related to a problem? Please describe. If no global recommendations are required (e.g. if active-learning is not enabled), then it can be useful to only ask for recommendations of the part of the document that the user is currently viewing.

Describe the solution you'd like Add (optional) offsets to the predict calls.

To do

• [x] Add PredictionCapability (text-only or uses-annotation)
• [ ] Consider the PredictionCapability during a prediction run
• [x] Add method to check which area is affected by an AnnotationEvent because that area should then be considered for an updated prediction (getAffectedRange())
• [x] Add option range parameters to predict call
• [ ] When an annotation is made, forward the affected range of the change to the prediction call so that the recommender has the option of limiting the prediction to that area
• [ ] When picking up suggestions from a recommender, inherit anything outside the range requested for prediction and only merge suggestions genererated within the range
• [ ] Implement recommendation merging test for the RecommendationServiceImpl