As it turns out, SkPath already behaves the way we need for SVG and HTML
canvas elements. Less work for us, yay! This removes a 5% item from the
profile when scrolling on https://imdb.com/
Note that there's a tiny screenshot test expectation change due to
minor antialiasing differences when we no longer do our redundant
subpath modifications.
`aa_translation` is something we inherited from times when
AntiAliasingPainter was a thing. This change replaces it by applying
offset directly to path.
Canvas text painting needs to support per-glyph font fallbacks, which
means we can't hand over responsibility for text shaping to Skia and
instead need to extract glyph paths from our own shaped GlyphRun.
