Bug 1661139: add delete option in view screen

option to delete page is enable for:
    - Normal user in its own pages
    - For group pages
        To admin user
        To other roles if they have Create and Edit permission
         in group setting and page is not locked
    - For institution, to site admin

behatnotneeded

Change-Id: I424c8a103e55d46178d779b77ebfb79db2d504f3