Accessibility fixes for confluence-space-ia bundled plugin

Problem Definition

Currently there are a few accessibility issues with the templates for this plugin, it is missing some accessibility code:

• sidebar.css
  add .anonymous css classes to adjust sidebar footer it anonymous
• sidebar-ia.js (and sidebar-ia-min.js)
  Add an auto expand feature when tabbing to sidebar when it is collapsed Allow enter/return to activate the expand collapse trigger.
  Update aria-expanded attributes on expand/collapse
• sidebar-space-tools.js (and sidebar-space-tools-min.js)
  Update aria-expanded attributes on expand/collapse
• space-menu.js (and space-menu-min.js)
  force selection of first item in spaces header dropdown menu when clicked.
• configurable-nav.js (and configurable-nav-min.js)
  Add aria-label to hide-link class