Bug 179931 Provide new interface IStyle to let extension return the style properties values
Provide the IStyle interface to let extension user can return the style property value list for their extension elements.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/extension/PeerExtensionTest.java
/*******************************************************************************
 * Copyright (c) 2004 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/
package org.eclipse.birt.report.model.extension;
import java.util.List;
import org.eclipse.birt.report.model.api.ActionHandle;
import org.eclipse.birt.report.model.api.DesignElementHandle;
import org.eclipse.birt.report.model.api.ExtendedItemHandle;
import org.eclipse.birt.report.model.api.GridHandle;
import org.eclipse.birt.report.model.api.ImageHandle;
import org.eclipse.birt.report.model.api.LabelHandle;
import org.eclipse.birt.report.model.api.ListHandle;
import org.eclipse.birt.report.model.api.ModuleUtil;
import org.eclipse.birt.report.model.api.PropertyHandle;
import org.eclipse.birt.report.model.api.SlotHandle;
import org.eclipse.birt.report.model.api.StyleHandle;
import org.eclipse.birt.report.model.api.TableGroupHandle;
import org.eclipse.birt.report.model.api.TableHandle;
import org.eclipse.birt.report.model.api.activity.SemanticException;