Floating point field for uniform scaling

[ygoumaz]

When scaling a Solid containing a Shape as a child along a specific axis, the scaling is performed along all axes at the same time (uniform scaling). Although it is mentioned in the documentation that physical objects can be restricted to uniform scaling, it seems strange that the scale field is always displayed as a 3D vector in the scene tree. It would probably be clearer to have a single factor to enter for these cases.