[GREENFOOT-713] An empty stage changes its location and size if a new scenario is opened.

The correct behaviour for different cases as agreed:

In case of a new window opened for this scenario: all properties should be loaded from the project's properties file, if they available.

In case of existing empty window: location of the window shouldn't change; the width/height should only get bigger if the value from the properties bigger than the current one.

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Issue metadata

• Issue type: Task
• Priority: Medium