Update the PAL::CryptoDigest class to accept and return Span objects.
<rdar://problem/103643663>
Pull request: https://github.com/WebKit/WebKit/pull/26217
Committed 276507@main (7638ebd71985): <https://commits.webkit.org/276507@main> Reviewed commits have been landed. Closing PR #26217 and removing active labels.