Convert APIError, APIFrameHandle, APIPageHandle, APIURL, APIURLRequest, and APIURLResponse types to use the new generated serializers.
<rdar://problem/103646493>
Pull request: https://github.com/WebKit/WebKit/pull/8015
Committed 258400@main (7e720e06b117): <https://commits.webkit.org/258400@main> Reviewed commits have been landed. Closing PR #8015 and removing active labels.