Bug 210716 Support switch Text/Chart view in crosstab cell
Need crosstab UI provide support to switch between Text and Chart view in measure/aggregation cell.
xtab/org.eclipse.birt.report.item.crosstab.core/src/org/eclipse/birt/report/item/crosstab/core/util/CrosstabUtil.java
public static IReportItem getReportItem( DesignElementHandle element,
			String extensionName )
	{
		if ( !( element instanceof ExtendedItemHandle ) )
			return null;
		if ( extensionName == null )
			throw new IllegalArgumentException( "extension name can not be null" ); 
		ExtendedItemHandle extendedItem = (ExtendedItemHandle) element;
		if ( extensionName.equals( extendedItem.getExtensionName( ) ) )
		{
			try
			{
				return extendedItem.getReportItem( );
			}
			catch ( ExtendedElementException e )
			{
				return null;
			}
		}
		return null;
	}
	/**
	 * Check the containment logic for dimension from outside of crosstab
	 * 
	 * @param crosstab
	 * @param axisType
	 * @param dimension
	 * @return
	 */
	public static boolean canContain( CrosstabReportItemHandle crosstab,