Navigation block accessibility

Hello

The entire navigation block doesn't work for people using screen readers / tabbing to go through links. We've been advised by Blazie (a consultancy specialising in accessibility this is a WCAG fail).

I have also removed a spurious image for site home and moved that into the CSS

There is a branch with fixes available here - https://github.com/pgogy/moodle/tree/NavigationBlockAccessibility

Look in blocks / navigation

and

lib/amd/src/tree.js

Thanks