Harmonize default dimensions and values with Quick 3D

We use the builtin Quick 3D meshes #Rectangle, #Cube and #Sphere for our examples. All these meshes are sized 100. Therefore we scale the models with 0.01 in most of our examples. Also other physically based rendering properties in Quick 3D are based on these default sizes which would lead to the need to scale either these values or 3D Physics values. This can be confusing to the user so these default values should be harmonized.