Refactor user ID access in SignalR hubs and add online user tracking

Introduces IHubUserAccessor and its implementation to centralize user ID retrieval from SignalR HubCallerContext, replacing duplicated logic in ChatsHub, FriendsHub, and PresenceHub. Moves extension and mapping files to a Common directory, adds UserToUserDtoMappingAction for online status mapping, and implements OnlineUserStore with tests for tracking online users. Updates dependency injection and test code to use the new abstractions.

Govor.API.Tests/IntegrationTests/Hubs/FriendsHubTests.cs

@@ -1,5 +1,6 @@
 using AutoFixture;
 using AutoMapper;
+using Govor.API.Common.SignalR.Helpers;
 using Govor.API.Hubs;
 using Govor.Application.Exceptions.FriendsService;
 using Govor.Application.Interfaces.Friends;
@@ -17,7 +18,7 @@ namespace Govor.API.Tests.IntegrationTests.Hubs;
 public class FriendsHubTests
 {
     private Mock<IFriendRequestCommandService> _friendRequestServiceMock = null!;
-    private Mock<ICurrentUserService> _currentUserServiceMock = null!;
+    private Mock<IHubUserAccessor> _currentUserServiceMock = null!;
     private Mock<IHubCallerClients> _clientsMock = null!;
     private Mock<IClientProxy> _clientProxyMock = null!;
     private Mock<ILogger<FriendsHub>> _loggerMock = null!;
@@ -35,19 +36,23 @@ public class FriendsHubTests
         _fixture.Behaviors.Add(new OmitOnRecursionBehavior());
         
         _friendRequestServiceMock = new Mock<IFriendRequestCommandService>();
-        _currentUserServiceMock = new Mock<ICurrentUserService>();
+        _currentUserServiceMock = new Mock<IHubUserAccessor>();
         _clientsMock = new Mock<IHubCallerClients>();
         _clientProxyMock = new Mock<IClientProxy>();
         _loggerMock = new Mock<ILogger<FriendsHub>>();
         _mapperMock = new Mock<IMapper>();
         
-        _currentUserServiceMock.Setup(x => x.GetCurrentUserId()).Returns(_userId);
+        _currentUserServiceMock.Setup(x => x.GetUserId(
+                It.IsAny<HubCallerContext>(),
+            It.IsAny<bool>()))
+            .Returns(_userId);
+        
         _clientsMock.Setup(c => c.Group(It.IsAny<string>())).Returns(_clientProxyMock.Object);
         
         _hub = new FriendsHub(
+            _loggerMock.Object,
             _friendRequestServiceMock.Object,
             _currentUserServiceMock.Object,
-            _loggerMock.Object,
            _mapperMock.Object)
         {
             Clients = _clientsMock.Object
@@ -129,7 +134,7 @@ public class FriendsHubTests
     public async Task SendRequest_ShouldReturnUnauthorized_WhenCurrentUserIsNotAuthenticated()
     {
         // Arrange 
-        _currentUserServiceMock.Setup(x => x.GetCurrentUserId())
+        _currentUserServiceMock.Setup(x => x.GetUserId(It.IsAny<HubCallerContext>(), It.IsAny<bool>()))
             .Throws(new UnauthorizedAccessException("userId claim is missing or invalid"));
 
         // Act