Switching between documents should be faster

[reckart]

Describe the bug The time INCEpTION takes to switch between documents is comparatively slow. For use-cases in which switching documents is common, it would be good if this could be improved. For example consider a case where the annotator skims from one document to the next in the search of a document that should be annotated.

Expected behavior Optimally, switching between documents should be as fast as paging within a document.

Please complete the following information:

• Version and build ID: 0.19.7