Organise frontend sidebar code

What does this MR do and why?

This MR organises frontend sidebar code:

• Updates imports inside ~/sidebar from ~/sidebar to ../*
• Moves constants and utils out of /components

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How to set up and validate locally

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.