In a previous commit the measure tool got the feature for displaying the area. In this commit we want to tweak this functionality.

Please do the following adjustments:

The new text should look like this

    Area:

180000 mi²

    (+)------------------

So the text should be

- wrapped into two lines, where the text is justified horizontally centered.

- positioned horizontally centered above the (+) icon (use the xOffset and yOffset of GeoPainter::drawText() to accomplish this)

- The values should be displayed in a form without "e"

- The unit should be miles or km depending on Marble's settings.