Adds move to option for modules

Makes the modules page more accessible for both screenreader and
keyboard only users.

fixes CNVS-9045

test plan:
  1. Using a screenreader go to the modules page (/courses/##/modules)
  2. The "keyboard instructions" area should inform you to use the
     move module options.
  3. Navigate to the admin links cog for a module
  4. You should see a "Move to..." option.
  5. Click it using whatever the screenreader uses for click
     (VO: Ctrl+Option+Space)
  6. A dialog should appear (This dialog should be accessible)
  7. You should be able to move a module to whatever location you
     want.
  8. Close the screenreader, repeat steps 3-7 using only the
     keyboard.
  9. When the drag-and-drop handle has focus a warning should appear.

Change-Id: Ie64b79ab6fa85d728fd97fba3842717b1a6ed99b
Reviewed-on: https://gerrit.instructure.com/39806
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>