Fix course title not showing on home front page

fixes LS-2605
flag=none

We recently switched to checking VIEW_ALL_PAGES for
VIEW_TOOLBAR as part of
[this change](https://gerrit.instructure.com/c/canvas-lms/+/270314)
which breaks for home pages because, unlike regular wiki show
pages, display_show_all_pages is false (we don't want to show
the All Pages button on the home page).

VIEW_TOOLBAR hides or shows the course title on the home page
so it needs to be true when course_home is true. There are
additional permission checks within VIEW_TOOLBAR so this does
not expose any other undesirable controls.

Test plan:
- Set a page as a front page
- Set a course home page to that front page
- View the course home as a student
- The course title should be displayed

Change-Id: I87b35a1c6bae16c7d092891015965b1817303d99
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/273182
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Robin Kuss <rkuss@instructure.com>
QA-Review: Robin Kuss <rkuss@instructure.com>
Product-Review: Nate Armstrong <narmstrong@instructure.com>

spec/coffeescripts/views/wiki/WikiPageViewSpec.js

@@ -315,3 +315,14 @@ testRights('CAN (manage, course home page)', {
     ACCESS_GEAR_MENU: true
   }
 })
+
+testRights('CAN (view toolbar on course_home)', {
+  course_home: true,
+  display_show_all_pages: false,
+  WIKI_RIGHTS: {
+    manage: false
+  },
+  CAN: {
+    VIEW_TOOLBAR: true
+  }
+})

ui/features/wiki_page_show/backbone/views/WikiPageView.js

@@ -272,6 +272,7 @@ export default class WikiPageView extends Backbone.View {
     json.CAN.DIRECT_SHARE = !!ENV.DIRECT_SHARE_ENABLED
     json.CAN.ACCESS_GEAR_MENU = json.CAN.DELETE || json.CAN.READ_REVISIONS || json.CAN.DIRECT_SHARE
     json.CAN.VIEW_TOOLBAR =
+      json.course_home ||
       json.CAN.VIEW_ALL_PAGES ||
       json.CAN.PUBLISH ||
       json.CAN.UPDATE_CONTENT ||