Add pages tree to the page navigation sidebar

• Type: Technical Task
• Status: Closed
• Priority: Minor
• Resolution: Completed
• Affects Version/s: None
• Fix Version/s: Master
• Component/s: WCM > Navigation
• Labels: None
• Sprint: S01E01 - Fruittis Volcano, S01E02 - Giants Enigma
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/79404

Add pages tree to the page navigation sidebar.