HDR / wide color gamut support

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Is your feature request related to a problem? Please describe.
Upcoming image formats for browsers (avif) will have support HDR /wide color gamut.
CanvasRenderingContext2d currently does not.
This suggests possible issues with regards to HDR support:

• what should happen to the HDR/gamut data when converting to formats that don't support it?
• what should happen to the HDR/gamut data when resizing an avif file?

Describe the solution you'd like

• figuring out how to handle import of HDR/gamut data
• figuring out how to handle export of HDR/gamut data
• development of general policy on how to handle features that image formats support but browsers don't provide native APIs for
• figure out if it's out-of-scope or not to add HDR/gamut data when manipulating an image in circumstances where squoosh transformations may benefit from doing so.

Additional context

• Summary of the wide gamut support on Canvas whatwg/html#4167