Refactor: migrate Core -> Domain and reorganize projects

Large refactor that renames/moves core types into a new Govor.Domain surface and reorganizes the Application layer. Models, configurations, migrations and many files moved from Govor.Core/Govor.Data to Govor.Domain; numerous Application services, interfaces and implementations were relocated or added (authentication, friends, messages, medias, push notifications, user sessions, storage, synching, private chats, etc.). Tests updated to use Govor.Domain namespaces and adjusted project references (removed Govor.Data reference from API tests). Also updated API, Hub and mapping code and project files to reflect the new structure and naming. This is primarily a codebase-wide namespace and module reorganization to establish a Domain project and restructure application services.

Govor.Application/Infrastructure/Extensions/CurrentUserService.cs

@@ -1,5 +1,3 @@
-using System.Security.Claims;
-using Govor.Application.Interfaces.Infrastructure.Extensions;
 using Microsoft.AspNetCore.Http;
 
 namespace Govor.Application.Infrastructure.Extensions;

Govor.Application/Infrastructure/Extensions/CurrentUserSessionService.cs

@@ -1,4 +1,3 @@
-using Govor.Application.Interfaces.Infrastructure.Extensions;
 using Microsoft.AspNetCore.Http;
 
 namespace Govor.Application.Infrastructure.Extensions;

Govor.Application/Infrastructure/Extensions/IConnectionStore.cs

@@ -0,0 +1,8 @@
+namespace Govor.Application.Infrastructure.Extensions;
+
+public interface IConnectionStore
+{
+    void AddConnection(Guid userId, string connectionId);
+    void RemoveConnection(Guid userId, string connectionId);
+    IEnumerable<string> GetConnections(Guid userId);
+}

Govor.Application/Infrastructure/Extensions/ICurrentUserService.cs

@@ -0,0 +1,6 @@
+namespace Govor.Application.Infrastructure.Extensions;
+
+public interface ICurrentUserService
+{
+    Guid GetCurrentUserId();
+}

Govor.Application/Infrastructure/Extensions/ICurrentUserSessionService.cs

@@ -0,0 +1,6 @@
+namespace Govor.Application.Infrastructure.Extensions;
+
+public interface ICurrentUserSessionService
+{
+    Guid GetUserSessionId();
+}

Govor.Application/Infrastructure/Extensions/IFriendsService.cs

@@ -0,0 +1,17 @@
+using Govor.Domain.Models;
+using Govor.Domain.Models.Users;
+
+namespace Govor.Application.Infrastructure.Extensions;
+
+public interface IFriendsService
+{
+    Task<List<User>> SearchUsersAsync(string query, Guid currentId);
+    Task SendFriendRequestAsync(Guid fromUserId, Guid toUserId);
+    Task AcceptFriendRequestAsync(Guid requestId, Guid currentUserId);
+    Task RejectFriendRequestAsync(Guid requestId, Guid currentUserId);
+    Task<List<User>> GetFriendsAsync(Guid userId);
+    Task<List<Friendship>> GetResponsesAsync(Guid userId);
+    Task<List<Friendship>> GetIncomingRequestsAsync(Guid userId);
+}
+
+