Refactor message service and move tests to Application.Tests

Renamed IMessageService to IMessageCommandService and updated all usages accordingly. Moved and renamed test files from Govor.API.Tests to the new Govor.Application.Tests project, updating namespaces to match. Refactored message-related services and controllers to use the new naming and structure. Added Govor.Application.Tests project to the solution.

Govor.Application/Infrastructure/AdminsStuff/InvitationGenerator.cs

@@ -0,0 +1,26 @@
+using Govor.API.Services.AdminsStuff.Interfaces;
+using Govor.Core.Models;
+using Govor.Core.Repositories.Invaites;
+
+namespace Govor.Application.Infrastructure.AdminsStuff;
+
+public class InvitationGenerator(IInvitesRepository repository) : IInvitationGenerator
+{
+    public async Task<string> GenerateInvitationCode(DateTime time, int maxUsers, bool isAdmin, string description = "")
+    {
+        Invitation newInvitation = new Invitation()
+        {
+            Id = Guid.NewGuid(),
+            Description = description,
+            MaxParticipants = maxUsers,
+            DateCreated = DateTime.UtcNow,
+            EndDate = time.ToUniversalTime(),
+            Code = Guid.NewGuid().ToString("N"),
+            IsAdmin = isAdmin
+        };
+
+       await repository.AddAsync(newInvitation);
+        
+        return newInvitation.Code;
+    }
+}

Govor.Application/Infrastructure/AdminsStuff/UsersService.cs

@@ -0,0 +1,36 @@
+using Govor.API.Services.AdminsStuff.Interfaces;
+using Govor.Core.Models;
+using Govor.Core.Repositories.Users;
+using Govor.Data.Repositories.Exceptions;
+
+namespace Govor.Application.Interfaces.AdminsStuff;
+
+public class UsersService : IUsersAdministration
+{
+    private readonly IUsersRepository _usersRepository;
+
+    public UsersService(IUsersRepository usersRepository)
+    {
+        _usersRepository = usersRepository;
+    }
+
+    public async Task<List<User>> GetAllUsersAsync()
+    {
+        try
+        {
+            var results = await _usersRepository.GetAllAsync();
+            return results;
+        }
+        catch (NotFoundException ex)
+        {
+            return new List<User>();
+        }
+    }
+
+    public async Task<User> GetUserById(Guid userId)
+    {
+        var result = await _usersRepository.FindByIdAsync(userId);
+            
+        return result;
+    }
+}