cursor controls to tweak slicers doesn't work on Mac

[jbfaden]

One should be able to use the cursor arrows on the keyboard to tweak the mouse position by pixel increments. This is useful for fine control to select ranges or positions. However, Dave noticed that this does not seem to work properly on a Mac. The pointer moves, but the feedback (crosshairs or serif bar) does not.

[jbfaden]

Here you can see where the pointer moves but the crosshair does not.

[jbfaden]

Also I believe some of the mouse actions don't support the arrow controls. All should support this (implementing them in a base case for example).