Add active bots connection to current user

[toland]

The client would like to have bots retrieved with the VISITOR relationship to be sorted by last visit time.

After further discussion on the referenced ticket, it turns out that the client needs a new activeBots connection on the currentUser object. For our purposes, a bot is "active" if the current user is a guest and the bot has visitors. The connection should be sorted by the most recent visit time of each bot. Also, when retrieving the subscribers connection on Bot, the client would like the connection sorted by visit time when the type is VISITOR.

The proposed structure for the connection is:

{
  currentUser {
    activeBots(first: 10) {
      edges {
        node {
          id
          description
          image {
            thumbnailUrl
          }
          subscribers(first: 5, type: VISITOR) {
            edges {
              node {
                id
                handle
              }
            }
          }
        }
      }
    }
  }
}

See this ticket for context.