Add experimental namespace_in_path pages url in deploy & Job artifacts

What does this MR do and why?

Add experimental namespace_in_path pages url in Project Deploy > Pages and Job artifacts.

Related to: GitLab Pages without DNS wildcard - MVC (#17584 - closed)

Changelog: added

Screenshots or screen recordings

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Before	After

How to set up and validate locally

1. After gdk reconfigure, add an entry namespace_in_path: true in gitlab-development-kit/gitlab/config/gitlab.yml under GitLabPages section
2. Restart the gdk using gdk restart.
3. Create a GitLab Pages website from a project template
4. Go to the created project > Deploy > Pages

Note: Clicking on experimental url will not display pages website in local, as it requires pages_nginx: omnibus-gitlab!7250 (merged)

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.