Add deprecated expand ratio methods to FormLayout (#12876)

FormLayout has never implemented expand ratios but does not
tell the developer about it either. Throwing an UnsupportedOperationException
would make this very clear but at the same time would break
existing applications which use the methods or which handle
AbstractOrderedLayouts in a generic way.

Change-Id: I0208f91c3c07aff98a78153887fbbea9dbc1d3d1

server/src/com/vaadin/ui/FormLayout.java

@@ -52,4 +52,23 @@ public class FormLayout extends AbstractOrderedLayout {
         addComponents(children);
     }
 
+    /**
+     * @deprecated This method currently has no effect as expand ratios are not
+     *             implemented in FormLayout
+     */
+    @Override
+    @Deprecated
+    public void setExpandRatio(Component component, float ratio) {
+        super.setExpandRatio(component, ratio);
+    }
+
+    /**
+     * @deprecated This method currently has no effect as expand ratios are not
+     *             implemented in FormLayout
+     */
+    @Override
+    @Deprecated
+    public float getExpandRatio(Component component) {
+        return super.getExpandRatio(component);
+    }
 }