Move Zoom value to Configurations
Panning in PanMode also update WorkspaceModel's offset without triggering its PropertyChanged
Remove mouse area, it was not needed due to EndlessGrid
Adding removal of registration of event handlers during DataContextChanged to
prevent binding multiple event handlers on the same datacontext causing one
operation to run multiple times on dynWorkspaceView.
Merge pull request #882 from l2obin/MAGN-741

MAGN-741 Fixed Zoom level is too fast after fit view or switching workspace