add require_admin: to individual view and cards options

[Mariusthvdb]

aware we can set full dashboards using the require_admin: true option, it would still be very flexible and easy to configure if we could set this on a single view too. Even more so on individual cards.

That way, we can organize the views in a coherent way, and still safe a couple of those for the admin only. All other view could be seen by all.

We can reach the same end goal probably, but that would require the opposite workflow: add all users to all other views. besides that we would need the explicit user id, instead of the better require_admin: true

views:
  - title: Admin
    require_admin: true
    cards:
      ...

  - type: entities
    title: Only for admins
    require_admin: true
    entities:
      - sensor.secret1
      - sensor.seecret2

please consider?
thanks

https://next.home-assistant.io/lovelace/views/#visible
https://next.home-assistant.io/lovelace/dashboards/