Review default templates for "edit" links

[kaitlinnewson]

Describe the bug
As I've been reviewing theme updates for 3.5, I've noticed a few cases where templates are missing edit links, which take a logged in user (e.g. admin) to the location in the back-end to edit the page content. We should review and add these to make the user experience consistent, and add convenience for those editing content.

These may also need to be added to theme plugins which override the templates.

To Reproduce
Steps to reproduce the behavior:

1. Login as an admin user
2. Open various pages in the journal front-end
3. Note some missing potential edit links - e.g. privacy, editorial masthead, additional homepage content (when entered in back-end)

What application are you using?
OJS, OMP or OPS version main