feat(router): add argument for hostname in router (#545) (#550)
# What does this PR do?
In title. Adds argument `--hostname` in router to support something like
`--hostname ::`. Tested with
```commandline
cargo run -- --port 8080 --hostname ::
curl -I -X GET 'http://[::1]:8080/health' # failed before this commit
```
Trigger CI
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Co-authored-by: Phil Chen <philchen2000@gmail.com>