ECMS-5764: Slowness in UIJCRExplorerPortlet.processRender within ECMS Read document context. Backport to PLF 4.1.

Problem analysis
	- Slowness in UIJCRExplorerPortlet.processRender divided into slowness in UIJCRExplorerPortlet.showDocument and UIDocumentInfo process rendering

Fix description:
	- Get value of document title property instead of check existence first because "exo:title" have value in most of cases
	- Improve UIJCRExplorer.getChildrenList(): Only return child nodes for current page
	- Improve UIJCRExplorer.refreshExplorer(): Call UITreeExplorer.buildTree() just if explorer tab is current view of side bar
	- Move getActionList for context menu outside of UIJCRExplorer rendering

Conflicts:
	apps/portlet-explorer/src/main/webapp/groovy/webui/component/explorer/UIDocumentNodeList.gtmpl
	apps/resources-wcm/src/main/webapp/javascript/eXo/wcm/backoffice/private/WCMUtils.js
	core/services/src/main/java/org/exoplatform/services/cms/taxonomy/impl/TaxonomyServiceImpl.java
	core/webui-administration/src/main/java/org/exoplatform/ecm/webui/component/admin/unlock/UILockNodeList.java
	core/webui-explorer/src/main/java/org/exoplatform/ecm/webui/component/explorer/DocumentProviderUtils.java
	core/webui-explorer/src/main/java/org/exoplatform/ecm/webui/component/explorer/UIDocumentInfo.java
	core/webui-explorer/src/main/java/org/exoplatform/ecm/webui/component/explorer/UIJCRExplorer.java
	core/webui/src/main/java/org/exoplatform/ecm/webui/utils/Utils.java
	packaging/wcm/webapp/src/main/webapp/WEB-INF/conf/dms-extension/dms/artifacts/views/templates/ecm-explorer/ContentView.gtmpl