Restore shortcut links within the super sidebar

What does this MR do and why?

This ensures that all links needed for keyboard shortcuts to function exist and have the correct CSS classes when the new navigation is enabled.

Screenshots or screen recordings

No visual change.

How to set up and validate locally

1. Enable the new nav:

   1. Enable the feature flag:

      echo "Feature.enable(:super_sidebar_nav)" | rails c

   2. Enable the user setting from the user dropdown:

      

2. Try any of the supported keyboard shortcuts:
   • GO_TO_YOUR_TODO_LIST: shift+t
   • GO_TO_ACTIVITY_FEED: shift+a
   • GO_TO_YOUR_ISSUES: shift+i
   • GO_TO_YOUR_MERGE_REQUESTS: shift+m
   • GO_TO_YOUR_PROJECTS: shift+p
   • GO_TO_YOUR_GROUPS: shift+g
   • GO_TO_MILESTONE_LIST: shift+l
   • GO_TO_YOUR_SNIPPETS: shift+s
   • GO_TO_YOUR_REVIEW_REQUESTS: shift+r

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 #393189 (closed)