closes https://github.com/TryGhost/Team/issues/1028
Bulk operations - add/remove label, unsubscribe - were added to filtered members list behind filtering labs flag as part of introducing filtering on members list. This handles the success/error response on bulk operations and shows them in the popup similar to delete bulk operation.
closes https://github.com/TryGhost/Team/issues/969
Wires the bulk action operation UI to Ghost API to perform operations on filtered member list - unsubscribe filtered members, add label to filtered members or remove label from filtered members
refs https://github.com/TryGhost/Team/issues/969
A lot of power of filtering members comes from ability to perform actions on the filtered member list. This change adds bulk operation actions on the the UI to apply on filtered members, but has not wired them up to the API yet.
- adds unsubscribe bulk operation UI
- adds label addition bulk operation UI
- adds label removal bulk operation UI
- adds new single label selection UI for add/remove label to members UI
