Proposals/dropsvgpathseginterfaces

Proposal

Remove (or alternatively deprecate) the SVGPathSeg* interfaces and attributes/methods using these.

Rationale

The usage of the SVGPathSeg* interfaces is zero in Blink, see UseCounter.

The counter measures use of all the createSVGPathSeg* methods and the {animated|normalized}pathSegList accessors as well as SVGPathSegList.