[Draft] Add better error message in get_svg for direction

An AttributeError is raised when `direction=Vector(0,0,0)` and obj is
an Arch::Space on line: a3fb3cc804/src/Mod/Draft/draftfunctions/svg.py (L799)

This patch checks if early on if the direction vector and raises a
ValueError with a description of what has gone wrong.

A caveat with this solution is that this new behaviour might break old
code which depends on that invalid directions can be used.

src/Mod/Draft/draftfunctions/svg.py

@@ -468,6 +468,8 @@ def get_svg(obj,
                 plane.alignToPointAndAxis_SVG(App.Vector(0, 0, 0),
                                               direction.negative().negative(),
                                               0)
+            else:
+                raise ValueError("'direction' cannot be: Vector(0, 0, 0)")
         elif isinstance(direction, WorkingPlane.plane):
             plane = direction