Allow unhandled custom uri-scheme opens to create QFileInfoEvent

On macOS custom uri-scheme opens may generate a QFileOpenEvent that
the applications can handle. However when adding support also for
QDesktopServices::setUrlHandler(), this delivery mechanism stopped
from working because the event was unconditionally consumed /
delivered to only the url handler.

Instead change the logic such that if the url handler does not
handle it, allow a QFileInfoEvent to be created.

Amends: 664c7ffb21

Fixes: QTBUG-134316
Change-Id: Ib1ed371ef531586bf549cf473b2a54748584d91d
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 4755f52c08aac424b18ad94404ca8f7dabf8220d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 0c7bea06c4871d25ebd334512cf1c38879b4b547)
(cherry picked from commit 73cfaa713d2dbb92a45cd5ad7bfdedbfa21eebd7)

src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm

@@ -343,8 +343,8 @@ QT_USE_NAMESPACE
             return;
         QCocoaIntegration *cocoaIntegration = QCocoaIntegration::instance();
         Q_ASSERT(cocoaIntegration);
-        cocoaIntegration->services()->handleUrl(QUrl(qurlString));
-        return;
+        if (cocoaIntegration->services()->handleUrl(QUrl(qurlString)))
+            return;
     }
 
     // The string we get from the requesting application might not necessarily meet