We were returning too many select options for the restricted link reach:
- when the "restricted" reach is an option (key present in the returned
dictionary), the possible values for link roles are now always None to
make it clearer that they don't matter and no select box should be
shown for roles.
- Never propose "restricted" as option for link reach when the ancestors
already offer a public access. Indeed, restricted/editor was shown when
the ancestors had public/read access. The logic was to propose editor
role on more restricted reaches... but this does not make sense for
restricted since the role does is not taken into account for this reach.
Roles are set by each access line assign to users/teams.