v2alpha1 node service (#5737)

getting node status:
```
> grpcurl -plaintext -d '{}' 127.0.0.1:9092 spacemesh.v2alpha1.NodeService.Status

{
  "connectedPeers": "111",
  "status": "SYNC_STATUS_SYNCING",
  "latestLayer": 50373,
  "appliedLayer": 50372,
  "processedLayer": 50372,
  "currentLayer": 54315
}

```

api/grpcserver/config.go

@@ -42,14 +42,15 @@ const (
 	RewardV2Alpha1           Service = "reward_v2alpha1"
 	RewardStreamV2Alpha1     Service = "reward_stream_v2alpha1"
 	NetworkV2Alpha1          Service = "network_v2alpha1"
+	NodeV2Alpha1             Service = "node_v2alpha1"
 )
 
 // DefaultConfig defines the default configuration options for api.
 func DefaultConfig() Config {
 	return Config{
 		PublicServices: []Service{
 			GlobalState, Mesh, Transaction, Node, Activation, ActivationV2Alpha1,
-			NetworkV2Alpha1,
+			RewardV2Alpha1, NetworkV2Alpha1, NodeV2Alpha1,
 		},
 		PublicListener: "0.0.0.0:9092",
 		PrivateServices: []Service{

api/grpcserver/v2alpha1/node.go

@@ -0,0 +1,83 @@
+package v2alpha1
+
+import (
+	"context"
+
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	spacemeshv2alpha1 "github.com/spacemeshos/api/release/go/spacemesh/v2alpha1"
+	"google.golang.org/grpc"
+
+	"github.com/spacemeshos/go-spacemesh/common/types"
+	"github.com/spacemeshos/go-spacemesh/timesync"
+)
+
+const (
+	Node = "node_v2alpha1"
+)
+
+// nodePeerCounter is an api to get current peer count.
+type nodePeerCounter interface {
+	PeerCount() uint64
+}
+
+// nodeMeshAPI is an api for getting mesh status.
+type nodeMeshAPI interface {
+	LatestLayer() types.LayerID
+	LatestLayerInState() types.LayerID
+	ProcessedLayer() types.LayerID
+}
+
+// nodeSyncer is an API to get sync status.
+type nodeSyncer interface {
+	IsSynced(context.Context) bool
+}
+
+func NewNodeService(peers nodePeerCounter, msh nodeMeshAPI, clock *timesync.NodeClock, syncer nodeSyncer) *NodeService {
+	return &NodeService{
+		mesh:        msh,
+		clock:       clock,
+		peerCounter: peers,
+		syncer:      syncer,
+	}
+}
+
+type NodeService struct {
+	mesh        nodeMeshAPI
+	clock       *timesync.NodeClock
+	peerCounter nodePeerCounter
+	syncer      nodeSyncer
+}
+
+func (s *NodeService) RegisterService(server *grpc.Server) {
+	spacemeshv2alpha1.RegisterNodeServiceServer(server, s)
+}
+
+func (s *NodeService) RegisterHandlerService(mux *runtime.ServeMux) error {
+	return spacemeshv2alpha1.RegisterNodeServiceHandlerServer(context.Background(), mux, s)
+}
+
+// String returns the service name.
+func (s *NodeService) String() string {
+	return "NodeService"
+}
+
+func (s *NodeService) Status(ctx context.Context, _ *spacemeshv2alpha1.NodeStatusRequest) (
+	*spacemeshv2alpha1.NodeStatusResponse, error,
+) {
+	var status spacemeshv2alpha1.NodeStatusResponse_SyncStatus
+
+	if s.syncer.IsSynced(ctx) {
+		status = spacemeshv2alpha1.NodeStatusResponse_SYNC_STATUS_SYNCED
+	} else {
+		status = spacemeshv2alpha1.NodeStatusResponse_SYNC_STATUS_SYNCING
+	}
+
+	return &spacemeshv2alpha1.NodeStatusResponse{
+		ConnectedPeers: s.peerCounter.PeerCount(),
+		Status:         status,
+		LatestLayer:    s.mesh.LatestLayer().Uint32(),        // latest layer node has seen from blocks
+		AppliedLayer:   s.mesh.LatestLayerInState().Uint32(), // last layer node has applied to the state
+		ProcessedLayer: s.mesh.ProcessedLayer().Uint32(),     // last layer whose votes have been processed
+		CurrentLayer:   s.clock.CurrentLayer().Uint32(),      // current layer, based on clock time
+	}, nil
+}