<url>: mention which properties have CORS restrictions

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/url

What specific section or headline is this issue about?

New section

What information was incorrect, unhelpful, or incomplete?

This page doesn't say which properties accept file: URLs and which don't. From https://github.com/mdn/content/issues/29106, it seems all new properties have CORS requirements.

What did you expect to see?

Two things:

• On the <url> page, two lists of properties that have CORS restrictions and those that don't
• For those properties with CORS, the same note as https://github.com/mdn/content/pull/34938 added to the property value DL.

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

This likely depends on https://github.com/mdn/content/issues/35029 so we can document it on <url> instead of url(), but we may also just document it on this page first, and then decide where to put this information later.