Add delete backtests by filters

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

@@ -41,6 +41,7 @@ public interface IBacktestRepository
     Task DeleteBacktestsByIdsForUserAsync(User user, IEnumerable<string> ids);
     void DeleteAllBacktestsForUser(User user);
     Task DeleteBacktestsByRequestIdAsync(Guid requestId);
+    Task<int> DeleteBacktestsByFiltersAsync(User user, BacktestsFilter filter);
 
     // Bundle backtest methods
     void InsertBundleBacktestRequestForUser(User user, BundleBacktestRequest bundleRequest);