Add option to show positive predictions for unlabeled elements only

[yannisk2]

Is your feature request related to a problem?
The positive predictions panel, while very useful, currently shows positive predictions for all elements (incl. the ones that the user has already labeled). As a result, when the user switches to this panel to provide feedback to the model predictions, they often have to go through elements they have already labeled, which can be inefficient.

What is the expected behavior?
To make the process of providing feedback to model predictions more efficient, it may help to allow the user to see the positive predictions only for elements that they have not labeled yet. As a design suggestion, we could add to the positive predictions panel a filtering functionality, which would allow the user to see positive predictions for either (a) all elements or (b) only the ones that they have not already labeled.