Versioning of UI and grpc-agent for passing version (#324)

Send Desktop UI client version as user-agent to daemon

This is sent on every login request to the management

Parse the GRPC context on the system package and 
retrieves the user-agent

Management receives the new UIVersion field and 
store in the Peer's system meta

client/ui/client_ui.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"github.com/cenkalti/backoff/v4"
+	"github.com/netbirdio/netbird/client/system"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -15,6 +15,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/cenkalti/backoff/v4"
+
 	_ "embed"
 
 	"github.com/getlantern/systray"
@@ -450,6 +452,7 @@ func (s *serviceClient) getSrvClient(timeout time.Duration) (proto.DaemonService
 		strings.TrimPrefix(s.addr, "tcp://"),
 		grpc.WithTransportCredentials(insecure.NewCredentials()),
 		grpc.WithBlock(),
+		grpc.WithUserAgent(system.GetDesktopUIUserAgent()),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("dial service: %w", err)