title editing on the wiki index page

test plan:
 - with draft state enabled
 * create several wiki pages
 * navigate to the index page (/courses/.../pages)
 * edit the title of one of the pages
   - the list of pages should not be duplicated

 - other wiki functionality should remain intact

fixes CNVS-11741

Change-Id: Iab1889671f9f706d8266df3051f660f6882995ca
Reviewed-on: https://gerrit.instructure.com/34216
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Nathan Rogowski <nathan@instructure.com>