[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

shared/relay/client/dialer/ws/conn.go

@@ -0,0 +1,67 @@
+package ws
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/coder/websocket"
+)
+
+type Conn struct {
+	ctx context.Context
+	*websocket.Conn
+	remoteAddr WebsocketAddr
+}
+
+func NewConn(wsConn *websocket.Conn, serverAddress string) net.Conn {
+	return &Conn{
+		ctx:        context.Background(),
+		Conn:       wsConn,
+		remoteAddr: WebsocketAddr{serverAddress},
+	}
+}
+
+func (c *Conn) Read(b []byte) (n int, err error) {
+	t, ioReader, err := c.Conn.Reader(c.ctx)
+	if err != nil {
+		// todo use ErrClosedByServer
+		return 0, err
+	}
+
+	if t != websocket.MessageBinary {
+		return 0, fmt.Errorf("unexpected message type")
+	}
+
+	return ioReader.Read(b)
+}
+
+func (c *Conn) Write(b []byte) (n int, err error) {
+	err = c.Conn.Write(c.ctx, websocket.MessageBinary, b)
+	return 0, err
+}
+
+func (c *Conn) RemoteAddr() net.Addr {
+	return c.remoteAddr
+}
+
+func (c *Conn) LocalAddr() net.Addr {
+	return WebsocketAddr{addr: "unknown"}
+}
+
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	return fmt.Errorf("SetReadDeadline is not implemented")
+}
+
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	return fmt.Errorf("SetWriteDeadline is not implemented")
+}
+
+func (c *Conn) SetDeadline(t time.Time) error {
+	return fmt.Errorf("SetDeadline is not implemented")
+}
+
+func (c *Conn) Close() error {
+	return c.Conn.CloseNow()
+}