Bug 212497 Need api to get all referencable report item with cube
Need model provide new api to return all referencable report items for dataset or cube respectively. For instance: getAvailableDataSetBindingReferenceList(); getAvailableCubeBindingReferenceList(); also keep current api: getAvailableDataBindingReferenceList().
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ReportItemHandle.java
IStyledElementModel,
			IReportItemMethodContext
{
	/**
	 * Data binding type "none".
	 */
	public static final int DATABINDING_TYPE_NONE = 0;
	/**
	 * Data binding type "data", means the report item is binding to a data set
	 * or cube.
	 */
	public static final int DATABINDING_TYPE_DATA = 1;
	/**
	 * Data binding type "reportItemRef", means the report item is binding to
	 * another report item.
	 */
	public static final int DATABINDING_TYPE_REPORT_ITEM_REF = 2;
	/**
	 * Constructs the handle for a report item with the given design and
	 * element. The application generally does not create handles directly.
	 * Instead, it uses one of the navigation methods available on other element
	 * handles.
	 * 
	 * @param module
	 *            the module
	 * @param element
	 *            the model representation of the element
	 */
	public ReportItemHandle( Module module, DesignElement element )
	{