[#213] No preferences/ devices: Add warning banner that no notifications will be received

closes #213 (closed) closes https://gitlab.cern.ch/push-notifications/notifications-design/-/issues/46

• Related MR: https://gitlab.cern.ch/push-notifications/backend/-/merge_requests/226/

---

All global preferences disabled

---

Global preferences are not associated with any device

Use case: If user has no device associated with preference - preference page banner

---

No preferences associated with any device for a specific channel

---

Global preference with no device associated but channel preference correct

There is a global preference with no device but there is channel preference that has a device, but since we want global preferences to be correct, show a warning

---

All preferences disabled on channels list

Use case: If user has no preferences: site wide banner

---

No preferences for this channel

Use case: If user disables all default preferences for a channel and as no custom channel preferences - channel preference page banner