[misc] Move shared components to shared directory (#4286)

Moved the following directories:

```
  - management/client → shared/management/client
  - management/domain → shared/management/domain
  - management/proto → shared/management/proto
  - signal/client → shared/signal/client
  - signal/proto → shared/signal/proto
  - relay/client → shared/relay/client
  - relay/auth → shared/relay/auth
```

and adjusted import paths

client/internal/peer/conn.go

@@ -24,7 +24,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/peer/id"
 	"github.com/netbirdio/netbird/client/internal/peer/worker"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
-	relayClient "github.com/netbirdio/netbird/relay/client"
+	relayClient "github.com/netbirdio/netbird/shared/relay/client"
 	"github.com/netbirdio/netbird/route"
 	semaphoregroup "github.com/netbirdio/netbird/util/semaphore-group"
 )

client/internal/peer/signaler.go

@@ -4,8 +4,8 @@ import (
 	"github.com/pion/ice/v3"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
-	signal "github.com/netbirdio/netbird/signal/client"
-	sProto "github.com/netbirdio/netbird/signal/proto"
+	signal "github.com/netbirdio/netbird/shared/signal/client"
+	sProto "github.com/netbirdio/netbird/shared/signal/proto"
 )
 
 type Signaler struct {

client/internal/peer/status.go

@@ -21,8 +21,8 @@ import (
 	"github.com/netbirdio/netbird/client/internal/ingressgw"
 	"github.com/netbirdio/netbird/client/internal/relay"
 	"github.com/netbirdio/netbird/client/proto"
-	"github.com/netbirdio/netbird/management/domain"
-	relayClient "github.com/netbirdio/netbird/relay/client"
+	"github.com/netbirdio/netbird/shared/management/domain"
+	relayClient "github.com/netbirdio/netbird/shared/relay/client"
 	"github.com/netbirdio/netbird/route"
 )
 

client/internal/peer/worker_relay.go

@@ -9,7 +9,7 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
-	relayClient "github.com/netbirdio/netbird/relay/client"
+	relayClient "github.com/netbirdio/netbird/shared/relay/client"
 )
 
 type RelayConnInfo struct {