Jump to nearest visible column rather than hide cursor when jumping to hidden region in keyboard mode

In cursor mode, it is possible to jump to a hidden region via the 'C' or 'P' commands (and possibly 'S', also, for rows). After this, Jalview simply doesn't show the cursor in this case - which is confusing.

Either visible indication is needed that the cursor lies in a hidden region, OR jalview should relocate the cursor to the nearest visible region (or alternately, offer to show that hidden region???).