List more than 10 subfolders via URL
List more than 10 subfolders via URL

fixes MAT-58
flag=none

Test Plan:
 - Create a course and, on "Files", create
   any number of folders
- Inside one of those folders, repeat the first
  step, creating  more than 10 subfolders
- After creating the subfolders, click on any
  of them and check the URL. Make sure you
  can access it later, by copying it from
  clipboard or clicking it in your web browser
- Click on "Home" and, then, masquerade your
  user as a teacher
- After masquerading, access the subfolder
  with the URL previously saved. Now it is
  visible that the list of subfolders doesn't
  reduce the expected number of subfolders

Change-Id: I1b1fa8ca69eec58290d535443d5240637d73b345
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/283066
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Weston Dransfield <e9203059795dc94e28a8831c65eb7869e818825e@instructure.com>
QA-Review: Weston Dransfield <e9203059795dc94e28a8831c65eb7869e818825e@instructure.com>
Product-Review: David Lyons <c345b6495d82f574bde007a1165ad87fad2909cd@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms