Do we support multi group alias for one group or not?

[pkking]

Opened the issue because im confused by these code:

        if fas_group not in flask.g.user.user_teams:
            raise InsufficientRightsException(
                "User '{}' doesn't have access to fas group {}"
                .format(flask.g.user.username, fas_group))

        alias = form.name.data
        group = UsersLogic.get_group_by_fas_name_or_create(
            fas_group, alias)

        db.session.add(group)
        db.session.commit()

        flask.flash(
            "FAS group {} is activated in the Copr under the alias {} "
            .format(fas_group, alias)
        )
        return flask.redirect(url_for(
            "groups_ns.list_projects_by_group", group_name=alias))

The code above will allow user submit more than one alias for a group, but if the group already has a alias, it just will always return it instead of create another alias, so the code behave is wired:

1. if we allow multi alias for one group, the maybe we should make a new method get_group_by_fas_name_and_alias_or_create to both match the alias and group name
2. if just one alias is allowed, the redirect should be using group.name instead of alias

[praiskup]

There's just 1:1 mapping, and if form.validate_on_submit() does some checking. There's though a race condition that we should fix, perhaps by installing unique key

copr/frontend/coprs_frontend/coprs/models.py

Line 2210 in 7442ec4

fas_name = db.Column(db.String(127))

[pkking]

Otherwise, the form.validate_on_submit() just check if the alias already existed, but if we try to add another alias for a group, it will try to redirect to /group/g/<new alias>/coprs which will return 404, i think we should just redirect to /group/g/<existed alias>/coprs.