Go Implementation - Pages without DNS wildcard implementation

Summary

To eliminate the need for wildcard DNS, the namespace can be included in the URL path instead of the domain.
For example, https://name.pages.example.io/index.html would become https://pages.example.io/name/index.html.

We could utilize the existing gitlab_pages["namespace_in_path"] parameter and implement it at the instance level.

• A detailed discussion can be found here: gitlab#17584 (closed)
• Past tech eval issue: #1109 (closed), gitlab#29841 (closed)

In the PoC, it was decided to use handler approach.