Cleanup route handling (#542)

* mikrotik: allow to set DNS, wip: handle routes in wg-controller

* replace old route handling for local controller

* cleanup route handling for local backend

* implement route handling for mikrotik controller

internal/domain/interface_controller.go

@@ -0,0 +1,27 @@
+package domain
+
+import "context"
+
+type InterfaceController interface {
+	GetId() InterfaceBackend
+	GetInterfaces(_ context.Context) ([]PhysicalInterface, error)
+	GetInterface(_ context.Context, id InterfaceIdentifier) (*PhysicalInterface, error)
+	GetPeers(_ context.Context, deviceId InterfaceIdentifier) ([]PhysicalPeer, error)
+	SaveInterface(
+		_ context.Context,
+		id InterfaceIdentifier,
+		updateFunc func(pi *PhysicalInterface) (*PhysicalInterface, error),
+	) error
+	DeleteInterface(_ context.Context, id InterfaceIdentifier) error
+	SavePeer(
+		_ context.Context,
+		deviceId InterfaceIdentifier,
+		id PeerIdentifier,
+		updateFunc func(pp *PhysicalPeer) (*PhysicalPeer, error),
+	) error
+	DeletePeer(_ context.Context, deviceId InterfaceIdentifier, id PeerIdentifier) error
+	PingAddresses(
+		ctx context.Context,
+		addr string,
+	) (*PingerResult, error)
+}