Add `clipboardchange` event

[nasso]

Specification: https://w3c.github.io/clipboard-apis/#clipboard-event-clipboardchange

Not currently supported in any browser (I don't think?).

Blink: https://issues.chromium.org/issues/41442253

[Schweinepriester]

Chrome issued intent to ship in 143:

• https://mastodon.social/@intenttoship.dev@bsky.brid.gy/115416785945850059
• https://groups.google.com/a/chromium.org/g/blink-dev/c/UgYnldQ0-VY/m/ZfL5WdjeAAAJ
• https://chromestatus.com/feature/5085102657503232