feat(fakeip): support fakeip dns

[cubatic45]

Background

vless xudp improve:
daeuniverse/outbound#52

config example:

dns {
    ipversion_prefer: 4
    upstream {
        alidns: 'udp+tcp://223.5.5.5:53'
        fakeip: 'fakeip://198.18.0.1:53'
    }
    routing {
        request {
            qname(geosite:cn) -> alidns
            fallback: fakeip
        }
    }
}

Checklist

• The Pull Request has been fully tested
• There's an entry in the CHANGELOGS
• There is a user-facing docs PR against https://github.com/daeuniverse/dae

Full Changelogs

• [Implement ...]

Issue Reference

Closes #[issue number]

Test Result