Fix for T87654: SVG import parse error

Fix for SVG data when there is no space between some arguments in the arc command.
See T87654 for example files.

See https://www.w3.org/TR/SVG2/paths.html#TheDProperty for arguments to the elliptical arc curve commands.

Maniphest Tasks: T87654

Differential Revision: https://developer.blender.org/D11027