Add mock SVGImageElement interface to fix TIMEOUT WPT tests
which are related to ImageBitmap (html/canvas/*).
https://svgwg.org/svg2-draft/embedded.html#InterfaceSVGImageElement
Rationality of this change to fire event "error" on any attempt to fetch
image resource on href attribute change to not block WPT tests
execution.
Some WPT tests use the legacy namespace attribute "xlink:href", so
support for it was added to source code.
https://svgwg.org/svg2-draft/linking.html#XLinkHrefAttribute
- setAttributeNS("http://www.w3.org/1999/xlink", 'xlink:href', src);
Testing: Covered by existed WPT tests
- fetch/metadata/generated/svg-image*
- html/canvas/element/manual/*
- html/dom/idlharness.https.html
- html/semantics/embedded-content/the-canvas-element/*
- html/webappapis/scripting/events/event-handler-all-global-events.html
- mozilla/interfaces.https.html
Fixes: https://github.com/servo/servo/issues/35881
Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>
