QLabel: lay out text using a text control when label can get focus

QLabel ensures a text control in its focusInEvent, and from that point
on lays the text out using the control. A label with text control will
place the text so that there is space for a cursor and text selection,
resulting in text shifting when a label receives focus without having
had a text control before.

Instead of creating the control only on focusIn, ensure that it's
created for any QLabel that can receive focus.

Change-Id: I26c9df3affa08f2360ad4b94de43bd85e2e2e164
Fixes: QTBUG-84080
Pick-to: 5.15
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

src/widgets/widgets/qlabel_p.h

@@ -92,9 +92,11 @@ public:
     void _q_buddyDeleted();
 #endif
     inline bool needTextControl() const {
+        Q_Q(const QLabel);
         return isTextLabel
                && (effectiveTextFormat != Qt::PlainText
-                   || (textInteractionFlags & (Qt::TextSelectableByMouse | Qt::TextSelectableByKeyboard)));
+                   || (textInteractionFlags & (Qt::TextSelectableByMouse | Qt::TextSelectableByKeyboard))
+                   || q->focusPolicy() != Qt::NoFocus);
     }
 
     void ensureTextPopulated() const;