QXmlStreamEntityResolver: disable copying

It's a polymorphic class, so disable copying as we do for all other
interfaces, too.

Disabling the copy/move SMFs requires manually restoring the default
ctor.

[ChangeLog][QtCore][Potentially Source-Incompatible
Changes][QXmlStreamEntityResolver] Disabled the copy and move
constructors and assignment operators. You can still provide them for
your own subclasses, but you must do so explicitly.

Change-Id: Ie2460f88664198707fdd4119376503f81a0f2a8d
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

src/corelib/serialization/qxmlstream.h

@@ -206,7 +206,9 @@ typedef QList<QXmlStreamEntityDeclaration> QXmlStreamEntityDeclarations;
 
 class Q_CORE_EXPORT QXmlStreamEntityResolver
 {
+    Q_DISABLE_COPY_MOVE(QXmlStreamEntityResolver)
 public:
+    QXmlStreamEntityResolver() = default;
     virtual ~QXmlStreamEntityResolver();
     virtual QString resolveEntity(const QString& publicId, const QString& systemId);
     virtual QString resolveUndeclaredEntity(const QString &name);