Do an update all items after creating a new item

[hilaire]

With a script scanning for some properties in a canvas, it is important to update the whole items right after a new item was instantiated.

That way the script has a chance to perform its tasks. Otherwise it requires a manual canvas update (for example dragging any items in the canvas)

The following change makes it:

DrGeoPresenter>>readyToBuild
   [...]
   self domain updateAllMathItems