Purpose of this merge is to refactor, clarify and fix surveys access rights
and rules. Indeed currently surveys access rights and rules are not very
clear. This application is currently used mainly for external and public
surveys.

In this merge we clean access on survey models. Basically only surveys officers
and managers have access to the models. Other people including employees,
portal users and anonymous people users have to use the portal view and
dedicated routes instead of accessing data through the backend.

In this merge we also expand the access options of surveys. Surveys can be
public, limited to authenticated people, limited to employees or on invitation
only. Invite wizard has been redone to simplify it and better support those
options.

For more details about the content please have a look at each subcommits.

This merge is linked to task ID 1911586 and PR #28986.