Fix viewport transition when translating/resizing annotations

Viewport isn't centered on annotations when translating/resizing.
This is best seen if the page is zoomed in and annotation is translated so that
several viewport transitions had happened.
Using undo after translation will expose error.

Function moveViewportIfBoundingRectNotFullyVisible centers viewport based on
translated/resized annotation's bounding rectangle.
For that reason functions translateBoundingRectangle/adjustBoundingRectangle need
to return the same bounding rectangle as annotation's translate/adjust functions.