updater: refactoring and set DNS server correctly

- Fix CLI operation not setting DNS server
- Fix periodic operation not setting DNS server
- Set DNS address for resolution once at start for both CLI and periodic operation
- Inject resolver to each provider instead of creating it within
- Use resolver settings on every call to `.Resolve` method, instead of passing it to constructor
- Move out minServers check from resolver

internal/provider/wevpn/updater/servers.go

@@ -31,7 +31,8 @@ func (u *Updater) FetchServers(ctx context.Context, minServers int) (
 		hostnameToCity[hostname] = city
 	}
 
-	hostnameToIPs, warnings, err := u.presolver.Resolve(ctx, hostnames, minServers)
+	resolverSettings := parallelResolverSettings(hostnames)
+	hostnameToIPs, warnings, err := u.presolver.Resolve(ctx, resolverSettings)
 	for _, warning := range warnings {
 		u.warner.Warn(warning)
 	}