Fix Maps update

Various fixes about RollingGrid :

• Correctly reset maps display when reset button is clicked in Paraview plugin.
• Allow changing RollingGrid resolution and size with non-empty grid, without resetting it.
• When new frame does not fit into grid, roll map to center of new frame bounds.
• Cleaning.

@nick.laurenson @melanie.carriere @lea.vauchier @jerome.dias PTAL