Returns the SVGPathSegList mapping the normalized static 'd' attribute
of the element.
A normalized path is composed only of absolute moveto, lineto and
cubicto path segments (M, L and C). Using this subset, the path
description can be represented with fewer segment types. Be aware that
the normalized 'd' attribute will be a larger String that the original.
Relative values are transformed into absolute, quadratic curves are
promoted to cubic curves, and arcs are converted into one or more
cubic curves (one per quadrant).
Modifications to the normalized SVGPathSegList will result
in substituting the original path with a set of normalized path