UI: add option to bulk dismiss devices

In addition to accepting and rejecting multiple devices at once, users also want the option to dismiss multiple devices at the same time. For example, checking all pending devices and clicking to dimiss (not reject outright).

UX would be the same as accepting/rejecting – using the expand menu on the bottom right when devices are checked in the table.

Acceptance criteria

• Bulk operations are supported for authentication actions (dismiss, reject, decomission)
  • E.g. possible workflow: 1) filter on Pending devices, then 2) "Select all" then 3) "Dismiss" 4) Approve action (X devices will be dismissed, explanation... Confirm?)