Add GetBotByUserIdAndNameAsync method to IBotService and BotService

- Implemented GetBotByUserIdAndNameAsync in IBotService and BotService to retrieve a bot by user ID and name.
- Updated GetUserStrategyCommandHandler to utilize the new method for fetching strategies based on user ID.
- Added corresponding method in IBotRepository and PostgreSqlBotRepository for database access.

src/Managing.Application.Abstractions/Repositories/IBotRepository.cs

@@ -14,6 +14,7 @@ public interface IBotRepository
     Task<IEnumerable<Bot>> GetBotsByUserIdAsync(int id);
     Task<IEnumerable<Bot>> GetBotsByStatusAsync(BotStatus status);
     Task<Bot> GetBotByNameAsync(string name);
+    Task<Bot> GetBotByUserIdAndNameAsync(int userId, string name);
     
     /// <summary>
     /// Gets paginated bots with filtering and sorting