Create phoenix virtual server to serve http/s traffic

[abose]

• [x] Phoenix virtual server based on no-host server already integrated into phoenix.
• [x] Should serve files from native mount points.
• [x] Remove nohost server.
• [ ] Use a different domain other than phoenix root that inherits all cookies and site data.. Currently, the built-in server is integrated via #18 is hosted from the same URL as Phoenix. This would be problematic as the live previewed sites will inherit all permissions/cookies of phoenix.core.ai. We should move the preview server to a different domain to minimize the live preview security surface.
• [ ] Disable server from serving anything else than extensions dir for security and never serve user content from phcode domain