API improvement:

vtkAxis did not have an API to change minimum and maximum value
with one vtkChart::UpdateRange event.
This lead to inability to precisely shift an axis without temporarily
changing its range width (distance between minimum and maximum value),
and complexity and inefficiency when synchronizing axes
between multiple charts.

SetRange and SetUnscaledRange methods now invoke only one
vtkChart::UpdateRange event (after both minimum and maximum values
are updated).

Fixing minor issues:

1. Added a missing vtkCommand::InteractionEvent invocation
when vtkChartXY axes range are adjusted using ZoomAxis action
(this event indicates that the user adjusted axes and so the
application can propagate this change to other charts).

2. Fixed vtkChartXY transform computation logic

vtkChartXY unnecessarily recomputed transforms when axes
were modified after the chart's last modified timestamp.
ALso, vtkChartXY never recomputed transforms when chart
properties changed after axes changed, even when
recomputation would have been necessary.