Initialise collapsible super sidebar

What does this MR do and why?

Adds:

• Conditionally (Feature.enabled?(:super_sidebar_nav, current_user) && current_user&.use_new_navigation) rendered button to collapse super sidebar.
• Button to super sidebar to expand sidebar
• SuperSidebar class for toggle behaviour

Requirements:

• Toggle button in super sidebar to collapses the sidebar with "Collapse sidebar" tooltip
• Toggle button in breadcrumbs to expand the sidebar with "Expand sidebar" tooltip
• Sidebar automatically collapsed on viewports < 1200px
• Store sidebar expanded/collapsed state in cookie
• Animate the sidebar expanding/collapsing for Fixed and Fluid layouts
• Toggle button moves to being positioned in top left of page
• Toggle button is displayed within the breadcrumbs for Fluid layout, or if on Fixed and the viewport is ≤ 990

Screenshots or screen recordings

Fixed

Expanded

Collapsed

How to set up and validate locally

• Enable the feature flag

Feature.enable(:super_sidebar_nav)

• Enable the "New navigation" setting toggle from the user dropdown

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #378544 (closed)