HTML validator errors on course homepage

To reproduce:

1. Create a course with completion tracking enabled.
2. Add several sections.
3. Add several activities within these sections that have manual and automatic completion tracking set
4. Add some blocks in the course
5. Turn editing on
6. View page source
7. Copy the source
8. Paste it in the text area input of the Nu HTML Validator site.
9. Press Check
10. Expected: There are no errors at least
11. Actual: There are errors and warnings

Errors (Must-fix)

1. An element with "role=menuitem" must be contained in, or owned by, an element with "role=menubar" or "role=menu"
   • This is caused by the cog menu on the blocks when editing mode is turned on.
2. Element "div" not allowed as child of element "span" in this context.
   • This is caused by "span.inplaceeditable" that contains the activity instance on the course homepage.
3. Duplicate ID "changenumsections"
4. Unclosed div
   • This occurs when completion tracking is enabled and when activity completion conditions are displayed.

Warnings (Optional or can be possibly raised as separate issues)

1. The "aria-checked" attribute should not be used on an "input" element which has a type attribute whose value is "checkbox".
   • This points to the edit mode toggle element.
2. Possible misuse of "aria-label"
   • Notifications:

     <div class="count-container hidden" data-region="count-container" aria-label="There are 0 unread notifications">

   • Language selector:

     <div id="carousel-item-62861425434b6" class="carousel-item submenu" tabindex="-1" aria-label="Language selector">

   • Messaging:

     <span class="badge badge-primary bg-primary ml-2 hidden" data-region="contact-request-count" aria-label="There are 0 pending contact requests">

   • Messaging:

     <small class="hidden ml-1" data-region="section-total-count-container" aria-label=" total conversations"