Integrate changelog in frontend

What does this MR do and why?

It integrates the changelog in frontend of the admin controls.

It transforms and displays the changelog in the <namespace-limits-section>s, and refetches the data after updating the limits to show latest changes.

Screenshots or screen recordings

Before	After

Screencast
Screen_Recording_2023-07-19_at_12.39.10

How to set up and validate locally

• In bin/rails console run:

    Feature.enable(:namespace_limits_admin_dashboard)
    ::Gitlab::CurrentSettings.update(check_namespace_plan: true)

• Simulate saas and restart your gdk

  $ export GITLAB_SIMULATE_SAAS=1
  $ gdk restart

• Visit /admin/namespace_limits as root

• Update any limit and observe the changelog below it getting updated

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 #412837