Bulk actions: handle several conversations at once

Handle several conversations at once.

How to

1. In the conversation list, tick the relevant conversations (checkboxes appear on hover).
2. A bulk-actions bar shows at the top.
3. Choose the action: assign an agent, assign a team, add/remove labels, or change status (resolve, reopen, snooze).

Good to know: great for clearing a queue after a campaign, or mass-reassigning when an agent is away.