[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/management/client/rest/client.go

@@ -0,0 +1,172 @@
+package rest
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/netbirdio/netbird/management/server/http/util"
+)
+
+// Client Management service HTTP REST API Client
+type Client struct {
+	managementURL string
+	authHeader    string
+	httpClient    HttpClient
+
+	// Accounts NetBird account APIs
+	// see more: https://docs.netbird.io/api/resources/accounts
+	Accounts *AccountsAPI
+
+	// Users NetBird users APIs
+	// see more: https://docs.netbird.io/api/resources/users
+	Users *UsersAPI
+
+	// Tokens NetBird tokens APIs
+	// see more: https://docs.netbird.io/api/resources/tokens
+	Tokens *TokensAPI
+
+	// Peers NetBird peers APIs
+	// see more: https://docs.netbird.io/api/resources/peers
+	Peers *PeersAPI
+
+	// SetupKeys NetBird setup keys APIs
+	// see more: https://docs.netbird.io/api/resources/setup-keys
+	SetupKeys *SetupKeysAPI
+
+	// Groups NetBird groups APIs
+	// see more: https://docs.netbird.io/api/resources/groups
+	Groups *GroupsAPI
+
+	// Policies NetBird policies APIs
+	// see more: https://docs.netbird.io/api/resources/policies
+	Policies *PoliciesAPI
+
+	// PostureChecks NetBird posture checks APIs
+	// see more: https://docs.netbird.io/api/resources/posture-checks
+	PostureChecks *PostureChecksAPI
+
+	// Networks NetBird networks APIs
+	// see more: https://docs.netbird.io/api/resources/networks
+	Networks *NetworksAPI
+
+	// Routes NetBird routes APIs
+	// see more: https://docs.netbird.io/api/resources/routes
+	Routes *RoutesAPI
+
+	// DNS NetBird DNS APIs
+	// see more: https://docs.netbird.io/api/resources/routes
+	DNS *DNSAPI
+
+	// GeoLocation NetBird Geo Location APIs
+	// see more: https://docs.netbird.io/api/resources/geo-locations
+	GeoLocation *GeoLocationAPI
+
+	// Events NetBird Events APIs
+	// see more: https://docs.netbird.io/api/resources/events
+	Events *EventsAPI
+}
+
+// New initialize new Client instance using PAT token
+func New(managementURL, token string) *Client {
+	return NewWithOptions(
+		WithManagementURL(managementURL),
+		WithPAT(token),
+	)
+}
+
+// NewWithBearerToken initialize new Client instance using Bearer token type
+func NewWithBearerToken(managementURL, token string) *Client {
+	return NewWithOptions(
+		WithManagementURL(managementURL),
+		WithBearerToken(token),
+	)
+}
+
+// NewWithOptions initialize new Client instance with options
+func NewWithOptions(opts ...option) *Client {
+	client := &Client{
+		httpClient: http.DefaultClient,
+	}
+
+	for _, option := range opts {
+		option(client)
+	}
+
+	client.initialize()
+	return client
+}
+
+func (c *Client) initialize() {
+	c.Accounts = &AccountsAPI{c}
+	c.Users = &UsersAPI{c}
+	c.Tokens = &TokensAPI{c}
+	c.Peers = &PeersAPI{c}
+	c.SetupKeys = &SetupKeysAPI{c}
+	c.Groups = &GroupsAPI{c}
+	c.Policies = &PoliciesAPI{c}
+	c.PostureChecks = &PostureChecksAPI{c}
+	c.Networks = &NetworksAPI{c}
+	c.Routes = &RoutesAPI{c}
+	c.DNS = &DNSAPI{c}
+	c.GeoLocation = &GeoLocationAPI{c}
+	c.Events = &EventsAPI{c}
+}
+
+// NewRequest creates and executes new management API request
+func (c *Client) NewRequest(ctx context.Context, method, path string, body io.Reader, query map[string]string) (*http.Response, error) {
+	req, err := http.NewRequestWithContext(ctx, method, c.managementURL+path, body)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Add("Authorization", c.authHeader)
+	req.Header.Add("Accept", "application/json")
+	if body != nil {
+		req.Header.Add("Content-Type", "application/json")
+	}
+
+	if len(query) != 0 {
+		q := req.URL.Query()
+		for k, v := range query {
+			q.Add(k, v)
+		}
+		req.URL.RawQuery = q.Encode()
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode > 299 {
+		parsedErr, pErr := parseResponse[util.ErrorResponse](resp)
+		if pErr != nil {
+
+			return nil, pErr
+		}
+		return nil, errors.New(parsedErr.Message)
+	}
+
+	return resp, nil
+}
+
+func parseResponse[T any](resp *http.Response) (T, error) {
+	var ret T
+	if resp.Body == nil {
+		return ret, fmt.Errorf("Body missing, HTTP Error code %d", resp.StatusCode)
+	}
+	bs, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return ret, err
+	}
+	err = json.Unmarshal(bs, &ret)
+	if err != nil {
+		return ret, fmt.Errorf("Error code %d, error unmarshalling body: %w", resp.StatusCode, err)
+	}
+
+	return ret, nil
+}