Expose the reasons for prerender or prefetch cancellation in the API

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Use Case

As a front-end web developer, I'd like to read the reasons for prerender/prefetch cancellation via JavaScript so I track and identify which pages on a site fail to prerender/prefetch via the Speculation Rules API.

Background Info

• As of 2023-04-27 in Chrome 112, "Prerendering Status" is displayed in the Application Tab in DevTools, but that information is not readable via an API:

• bfcache has the NotRestoredReasons API which serves a similar purpose to the above use case.
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