rest-api: add RoleLimitedViewSet and change most views to inherit it

exceptions are:
* /login
* /logout
* /info which remains accessable to anyone so that bootstrapping can work

Signed-off-by: Gregory Meno <gmeno@redhat.com>
Merge pull request #225 from ceph/wip-10071

rest-api: add RoleLimitedViewSet and change most views to inherit it