Command palette scoped navigation

What does this MR do and why?

It mirrors all the sidebar navigation int the command palette. This could be easily achieved as all the data is already exposed from BE for the super sidebar.

How to set up and validate locally

👣 Enabled the feature flag

rails c 
Feature.enable(:command_palette)

👣 Click on the Global Search icon in the new navigation

👣 Search for some menu item from the sidebar. E.g. in project scope search for Repository graph

Note that so far we do not have distinct requirements so I've implemented it as I thought would be reasonable. Feel free to add ideas what could be the next commands in the command palette which you'd like to have access to. _

My plan is:

👣 Add epic, MR, project search by !, &, etc - !122515 (merged)

👣 some basic commands context-based - e.g. closing the issue on the issue page or promoting it to an epic. Or some ideas from &8912. Something that would be an easy win

This is an experimental functionality and is the subject of future change or complete removal - we'll get the UX input after a couple of basic experimental commands are added

Screenshots or screen recordings

Related to &8912