Cherry-pick 7807b5ccd64a. rdar://149217986

    Loosen WKWebViewConfiguration checks in UIDelegate::UIClient::createNewPage
    https://bugs.webkit.org/show_bug.cgi?id=291346
    rdar://148942809

    Reviewed by Charlie Wolfe.

    In 276636@main I added an additional check on the WKWebViewConfiguration of the created
    WKWebView that could not be synthesized by SPI.  In 285310@main I removed the _relatedWebView
    check which had been superseded.  rdar://148942809 contains a record that somewhere in
    Safari there is a WKWebView being returned that was not created with the given configuration.
    This reverts the check to how it was last year, only checking that _relatedWebView is correct
    if site isolation is off.  That should replace a crash with a missing opener.  Since a missing
    opener is also not great, I added a RELEASE_LOG_FAULT to give us the stack of where this is
    happening so that we can fix it.  I only set openerInfoOfPageBeingOpened in Mac Safari because
    that is the only user of _relatedWebView where this issue can arise.  It's also not technically
    a restriction that you can't create another WKWebView during a WKUIDelegate's
    createWebViewWithConfiguration call because you could be creating a WKWebView to do something
    with other than return it from createWebViewWithConfiguration, but in macOS Safari we know
    it is almost certainly the case that we only create one WKWebView, which means the stack we
    get from the RELEASE_LOG_FAULT should show us where the bug is.

    * Source/WebKit/UIProcess/Cocoa/UIDelegate.mm:
    (WebKit::crashWithUIDelegateClassName):
    (WebKit::UIDelegate::UIClient::createNewPage):

    Canonical link: https://commits.webkit.org/293537@main

Canonical link: https://commits.webkit.org/289651.426@safari-7621-branch