Added helper methods for setting only height or width full. (#11854)

server/src/main/java/com/vaadin/server/Sizeable.java

      */
     public void setSizeFull();
 
+    /**
+     * Sets the width to 100%.
+     *
+     * @since
+     */
+    public void setWidthFull();
+
+    /**
+     * Sets the height to 100%.
+     *
+     * @since
+     */
+    public void setHeightFull();
+
     /**
      * Clears any size settings.
      */

server/src/main/java/com/vaadin/ui/AbstractComponent.java

 import java.util.Set;
 import java.util.StringTokenizer;
 
-import com.vaadin.annotations.Theme;
-import com.vaadin.ui.themes.ValoTheme;
 import org.jsoup.nodes.Attribute;
 import org.jsoup.nodes.Attributes;
 import org.jsoup.nodes.Element;
         setHeight(100, Unit.PERCENTAGE);
     }
 
+    /*
+     * (non-Javadoc)
+     *
+     * @see com.vaadin.server.Sizeable#setWidthFull()
+     */
+    @Override
+    public void setWidthFull() {
+        setWidth(100, Unit.PERCENTAGE);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see com.vaadin.server.Sizeable#setHeightFull()
+     */
+    @Override
+    public void setHeightFull() {
+        setHeight(100, Unit.PERCENTAGE);
+    }
+
     /*
      * (non-Javadoc)
      *