Add unit tests and implement group repository interfaces

Introduces comprehensive unit tests for MessageService covering send, edit, and delete message scenarios. Adds and implements IGroupsRepository, IGroupsReader, and IGroupsWriter interfaces with method stubs in GroupRepository. Updates ChatGroup model with Description and ImageId fields, and registers GroupRepository in DI. Fixes parameter order in SendMessage record.

Govor.Data/Repositories/GroupRepository.cs

@@ -1,6 +1,62 @@
+using System.Text.RegularExpressions;
+using Govor.Core.Models;
+using Govor.Core.Repositories.Groups;
+
 namespace Govor.Data.Repositories;
 
-public class GroupRepository
+public class GroupRepository : IGroupsRepository
 {
+    public Task<List<Group>> GetAllAsync()
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task<Group> GetByIdAsync(Guid id)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task<List<Group>> FindByNameAsync(string name)
+    {
+        throw new NotImplementedException();
+    }
     
-}
+    public Task<List<Group>> GetByAdminIdAsync(Guid adminId)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task<List<Group>> GetByUserIdAsync(Guid adminId)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task Add(Group group)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task Update(Group group)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Task Remove(Guid groupId)
+    {
+        throw new NotImplementedException();
+    }
+    public bool Exists(Guid groupId)
+    {
+        throw new NotImplementedException();
+    }
+
+    public bool Exists(ChatGroup chatGroup)
+    {
+        throw new NotImplementedException();
+    }
+    
+    public bool IsUserMemberOfGroupAsync(Guid userId, Guid groupId)
+    {
+        throw new NotImplementedException();
+    }
+}