Adjust spacing in the sidebar to align elements

What does this MR do and why?

The top row of items in the navigation sidebar do not align with the breadcrumb, which creates an offset look. This swaps around the classes to balance the alignment and add spacing between top row items.

Closes #422559 (closed)

Screenshots or screen recordings

Before	After
Show sidebar	Show sidebar
Peek sidebar	Peek sidebar
Show sidebar when unauthenticated	Show sidebar when unauthenticated
Peek sidebar when unauthenticated	Peek sidebar when unauthenticated

How to set up and validate locally

View the sidebar in 2 different ways to see the impact of the spacing as a logged in user.

1. When the sidebar is shown as a logged in user
2. Hide the sidebar, and use the peek functionality as a logged in user

As a unauthenticated user, you'll need to enable a feature flag

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

1. When the sidebar is shown as an unauthenticated user
2. Hide the sidebar, and use the peek functionality an unauthenticated user

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.