LPS-35075 Creating LayoutStagedModelDataHandler and copy over related logic and methods (copy/paste)

Conflicts:
	portal-impl/src/com/liferay/portal/lar/LayoutImporter.java
LPS-35075  Registering new staged model data handler
LPS-35075 Changing method visibility scope for Permission/Portlet Exporter/Importer
LPS-35075 Slightly changing PortletDataContext to support LayoutSMDH
LPS-35075 Apply logic changes according to the new StagedModelDataHandler
LPS-35075 Source formatting ExportImportPathUtil