faculty journal entries for multiple student recipients

closes PS-1497, closes CNVS-13211

test plan pre-reqs:
  1. to go accounts/self
  2. turn on facutly journal entries

test plan:
  1. go to conversations
  2. select 1 student, you should be able to
     send a message with faculty journal checkbox
     checked
  3. select more than 1 student, you should be able
     to send a message with faculty journal checkbox
     checked
  4. select all students in a course, you should be
     able to send a message with faculty journal checkbox
     checked
  5. select a few students and a teacher / observer /
     ta and you should not see the faculty journal
     checkbox
  6. select all teachers in a course and you should
     not be able to see the facutly journal checkbox
  7. validate students receive faculty journal entries
     when checkbox is checked

NOTES: there is a canvas bug associated with this
       fix. If you check the faculty journal checkbox
       and you check the individual messages checkbox
       it will not send the journal entries because
       it does not follow the same flow.

Change-Id: I6661c1a51ab5f8e37a9dbd54bafd49be17594e61
Reviewed-on: https://gerrit.instructure.com/35091
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Joel Hough <joel@instructure.com>
Product-Review: Jake Sorce <jake@instructure.com>
QA-Review: Jake Sorce <jake@instructure.com>