When the Desktop Toolbox is dragged out of a corner, its label is shown. Currently this label is not very clear since it consists only of the name of the current activity, which by default is "Default".
This patch introduces three changes:
- When the label is shown, always prepend it with the widget's actual name: "Desktop Toolbox"
- Append the word "Activity" so it's obvious what the preceding string refers to
- Don't show the activity name if it's "Default" since this signifies that the user does not use Activities and would be confused by seeing references to a "Default Activity".