Add support of the ImageBitmapRenderingContext as "bitmaprenderer"
canvas context mode to RenderingContext/OffscreenRenderingContext
https://html.spec.whatwg.org/multipage/#imagebitmaprenderingcontext
It is initial implementation with public interface API but without
any display presentation support for HTMLCanvasElement.
Testing: Improvements in the following tests:
-
html/canvas/element/manual/imagebitmap/createImageBitmap-origin.sub.html
- html/canvas/offscreen/manual/text/canvas.2d.offscreen*
-
html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.nocrash.html
- imagebitmap-renderingcontext/*
Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>