Support new Management service protocol (NetworkMap) (#193)

* feature: support new management service protocol

* chore: add more logging to track networkmap serial

* refactor: organize peer update code in engine

* chore: fix lint issues

* refactor: extract Signal client interface

* test: add signal client mock

* refactor: introduce Management Service client interface

* chore: place management and signal clients mocks to respective packages

* test: add Serial test to the engine

* fix: lint issues

* test: unit tests for a networkMapUpdate

* test: unit tests Sync update

management/client/mock.go

@@ -0,0 +1,49 @@
+package client
+
+import (
+	"github.com/wiretrustee/wiretrustee/management/proto"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+type MockClient struct {
+	CloseFunc              func() error
+	SyncFunc               func(msgHandler func(msg *proto.SyncResponse) error) error
+	GetServerPublicKeyFunc func() (*wgtypes.Key, error)
+	RegisterFunc           func(serverKey wgtypes.Key, setupKey string) (*proto.LoginResponse, error)
+	LoginFunc              func(serverKey wgtypes.Key) (*proto.LoginResponse, error)
+}
+
+func (m *MockClient) Close() error {
+	if m.CloseFunc == nil {
+		return nil
+	}
+	return m.CloseFunc()
+}
+
+func (m *MockClient) Sync(msgHandler func(msg *proto.SyncResponse) error) error {
+	if m.SyncFunc == nil {
+		return nil
+	}
+	return m.SyncFunc(msgHandler)
+}
+
+func (m *MockClient) GetServerPublicKey() (*wgtypes.Key, error) {
+	if m.GetServerPublicKeyFunc == nil {
+		return nil, nil
+	}
+	return m.GetServerPublicKeyFunc()
+}
+
+func (m *MockClient) Register(serverKey wgtypes.Key, setupKey string) (*proto.LoginResponse, error) {
+	if m.RegisterFunc == nil {
+		return nil, nil
+	}
+	return m.RegisterFunc(serverKey, setupKey)
+}
+
+func (m *MockClient) Login(serverKey wgtypes.Key) (*proto.LoginResponse, error) {
+	if m.LoginFunc == nil {
+		return nil, nil
+	}
+	return m.LoginFunc(serverKey)
+}