vg_load_svg: Implement ClipPath feature

vg_load_svg: Implement ClipPath feature

Summary:
Supports case of using style attribute for defined <clipPath> and node.
In SVG, <clipPath> can be used as a "clipPath" attribute or a style "clip-path".
If there is a clip-path node, save it as a composition node and
use composition method(matte_alpha) to compose it.

Below node types support clip-path.
<circle>
<ellipse>
<g>
<path>
<polygon>
<polyline>
<rect>

Test Plan:
Please see attached svg files
{F4026162}

Reviewers: Hermet, smohanty

Reviewed By: Hermet

Subscribers: #reviewers, #committers, cedric, herb, kimcinoo

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D12179

Change-Id: I1e02b0405d32ebea4ba9b072586aaad7248ee598