Add clipboard support for image/webp

[BlackHC]

This requires using a canvas object to render the webp to png as image/webp is not supported (by Chromium at the very least).

Manually tested in Chrome 119.0.6045.199 (Official Build) (arm64).

[BlackHC]

Thank you so much for the approval.

1. For the two failing checks - is there any information on why they failed? I don't have access to the Azure logs.

2. I've been using this quite heavily, and there is a quirk I have found: when you click on copy, it takes a short amount of time to convert the webp to png for the clipboard blob. If the user clicks on the copy button and then immediately switches to a different window, the clipboard operation can fail with DOMException: Document is not focused. I don't think there is an easy fix.

I don't have the Javascript/VSCode knowledge to add a spinner or similar to the code, which might be a UX fix.

[DonJayamanne]

Apologies for never getting back on this,
will get this sorted out this week.