Make landing page heading more consistent
Landing pages use digital object labels as the heading -- but only if it is public. Instead, this label should also be used if I am allowed to read the label.
In cases where I am not allowed to read the label, the heading "Landing Page" is currently used. Maybe this could be replaced with something like "Digital Object {{ id }}" to make it more meaningful. While we're at it, the template block head
can now be used to set the page title. Also, make sure improve Open Graph metadata for landing pages. This can be done using the block that was introduced in !696 (merged).