Widgets that use digitization should relay status with MapMessage

[jng]

The problem with most widgets that currently use digitization (eg. Measure, Redline) is that from a UX perspective there is no "visual" status shouting out at you that digitization is currently in progress.

But we already have a component to do this: Fusion.MapMessage

We can improve UX in digitizing by flashing the Fusion.MapMessage when starting the digitization and dismissing it when the digitization is completed. This way, the user can "see" that the viewer is still in the state of digitization. This is also useful for catching bugs involving digitization as a MapMessage that isn't dismissed indicates a digitizer has not been properly deactivated.

[jng]

Left out FeatureInformation widget