An AttributeError is raised when `direction=Vector(0,0,0)` and obj is
an Arch::Space on line: bead9bb938/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.
This includes `auxiliary`, `draft_test_objects`, `test_airfoildat`,
`test_creation`, `test_dwg`, `test_dxf`, `test_import`,
`test_import_gui`, `test_import_tools`, `test_modification`,
`test_oca`, `test_pivy`, `test_svg`.
These are added to the `drafttests` Doxygen group
so that the functions and classes contained in each module
are listed appropriately in the automatically generated
documentation.
Also fix the name of certain functions.
Do not import `DraftFillet` any more as it's just kept
for compatibility purposes.
Do not test OCA nor AirfoilDAT as it's very improbable
that these formats will gain more support any time soon.
