Optimize `DNSResolveCacheController` type, including `dns.Server` optimization for easy start/stop. This PR ensures that we
delete server from runners on stop (even unexpected) and restart it properly. Also fixes incorrect assumption on unit-tests.
Fixes#8563
This PR also does those things:
- Removes `utils.Runner`
- Removes `ctxutil.MonitorFn`
- Removes `dns.Runner`
- Removes `network.dnsRunner`
Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>
ba7cdc8c8b