[SVG] Refactor getIntersectionList() and getEnclosureList()

LayoutTests/svg/dom/SVGSVGElement-intersection-enclosure-expected.txt

+Verify SVGSVGElement's getIntersectionList() and getEnclosureList() behavior.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+
+rect: [50 50 150 150]
+PASS svg.getEnclosureList(rect, null).length is 100
+PASS svg.getIntersectionList(rect, null).length is 100
+
+rect: [55 55 145 145]
+PASS svg.getEnclosureList(rect, null).length is 64
+PASS svg.getIntersectionList(rect, null).length is 100
+
+Zooming should not affect the results.
+
+rect: [50 50 150 150]
+PASS svg.getEnclosureList(rect, null).length is 100
+PASS svg.getIntersectionList(rect, null).length is 100
+
+rect: [55 55 145 145]
+PASS svg.getEnclosureList(rect, null).length is 64
+PASS svg.getIntersectionList(rect, null).length is 100
+
+But a viewbox transform should.
+
+rect: [50 50 150 150]
+PASS svg.getEnclosureList(rect, null).length is 36
+PASS svg.getIntersectionList(rect, null).length is 49
+
+rect: [55 55 145 145]
+PASS svg.getEnclosureList(rect, null).length is 25
+PASS svg.getIntersectionList(rect, null).length is 36
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+