Retrieve all Campaigns

**This endpoint allows you to retrieve a paginated list of all of your campaigns.** Returns campaigns in reverse order they were created (newest first). Returns an empty array if no campaigns exist. You can use the `limit` query parameter to set the page size. If your list contains more items than the page size permits, you can make multiple requests. Use the `offset` query parameter to control the position in the list from which to start retrieving additional items.