Replace BlobURLHandle class with a more generic class that can old non-blob URLs.
Pull request: https://github.com/WebKit/WebKit/pull/4120
Committed 254283@main (3aecdc0641da): <https://commits.webkit.org/254283@main> Reviewed commits have been landed. Closing PR #4120 and removing active labels.
<rdar://problem/99713556>
Bug 245815 – REGRESSION(254283@main): [WK1] fast/workers/worker-copy-shared-blob-url.html is crashing