Fix accessible label of checkboxes broken by recent changes

The fix for wxCheckBox accessibility in dark mode in b5ea9cfe86 (Fix
wxCheckBox and wxRadioButton accessibility in wxMSW dark mode,
2026-02-13) broke getting their label in the screen readers as this was
broken by default in wxWindowAccessible::GetName() which has started
being used for them.

Fix this by returning the label and not the (internal) name of the
control from wxWindowAccessible::GetName() by default, instead of only
doing this for wxButton.

See #26184, #26187.

Closes #26270.

src/common/wincmn.cpp

@@ -3887,15 +3887,7 @@ wxAccStatus wxWindowAccessible::GetName(int childId, wxString* name)
     if (childId > 0)
         return wxACC_NOT_IMPLEMENTED;
 
-    // This will eventually be replaced by specialised
-    // accessible classes, one for each kind of wxWidgets
-    // control or window.
-#if wxUSE_BUTTON
-    if (wxDynamicCast(GetWindow(), wxButton))
-        title = ((wxButton*) GetWindow())->GetLabel();
-    else
-#endif
-        title = GetWindow()->GetName();
+    title = GetWindow()->GetLabel();
 
     if (!title.empty())
     {