There are WPT tests that say we should throw a NotSupportedError when passed in an empty string for appid, but we currently do not do so.
Pull request: https://github.com/WebKit/WebKit/pull/27146
<rdar://problem/126692987>
Committed 279285@main (2d34e99f4cc7): <https://commits.webkit.org/279285@main> Reviewed commits have been landed. Closing PR #27146 and removing active labels.