Support to add prefix and extra header to address field

There should be a parameter to include a prefix in the address field. Currently, adding a complete URL to the address results in a `502 Bad Gateway` error. Additionally, a feature to include extra headers in the configuration should be supported.

The service configuration file (`aperture.yaml`) should look like this:
```
- name: "service1"
hostregexp: "^localhost:8081$"
pathregexp: '^/api$'
address: "0.0.0.0:443"
protocol: https
header:
Authorization: "Bearer key"
price: 10
rewrite:
prefix: "/path/to/api"
```

Start with the service configuration represented by aperture.yaml, then trace how address, protocol, and request forwarding are parsed and applied. Check existing proxy or configuration tests if present. Done means a complete URL address no longer causes a 502, rewrite.prefix is honored, and configured extra headers such as Authorization are forwarded.

Written by the indexing model from the issue text.