Display content ownership / responsibilities

As an editor i want to define a content ownership in backend and display it in FE and BE. An owner ship must be a person and (or) a group.

AC:

• Select a fe_user as content owner for a page
• select optional a fe_group for a page
• display the content ownership in list and page module as info in BE
• display the content ownership in frontend (maybe in footer somewhere)
• add a contact form, to get in touch with content owner