lib/config: Decouple VerifyConfiguration from Committer (#7939)

... and remove 8/10 implementations, which were no-ops. This saves code
and time copying configurations.

lib/connections/limiter.go

@@ -122,10 +122,6 @@ func (lim *limiter) processDevicesConfigurationLocked(from, to config.Configurat
 	}
 }
 
-func (lim *limiter) VerifyConfiguration(from, to config.Configuration) error {
-	return nil
-}
-
 func (lim *limiter) CommitConfiguration(from, to config.Configuration) bool {
 	// to ensure atomic update of configuration
 	lim.mu.Lock()

lib/connections/service.go

@@ -706,10 +706,6 @@ func (s *service) logListenAddressesChangedEvent(l ListenerAddresses) {
 	})
 }
 
-func (s *service) VerifyConfiguration(from, to config.Configuration) error {
-	return nil
-}
-
 func (s *service) CommitConfiguration(from, to config.Configuration) bool {
 	newDevices := make(map[protocol.DeviceID]bool, len(to.Devices))
 	for _, dev := range to.Devices {