Adding Async methods to verious services

SzCore/ISzFileManager.cs

@@ -1,15 +1,15 @@
-using System.Security.Cryptography.X509Certificates;
-using SzCore.DataObjects;
-
 namespace SzCore;
 
 public interface ISzFileManager 
 { 
-    public string DataPath {get;}
-    public string DatasetsPath {get;}
-    public string TemplatesPath {get;}
+    string DataPath { get; }
+    string DatasetsPath { get; }
+    string TemplatesPath { get; }
     
-    public bool SaveFile(string path, string fileContent);
-    public string? LoadFile(string path);
-    public bool DeleteFile(string path);
-}
+    bool SaveFile(string path, string fileContent);
+    string? LoadFile(string path);
+    bool DeleteFile(string path);
+
+    Task<bool> SaveFileAsync(string path, string fileContent, CancellationToken ct = default);
+    Task<string?> LoadFileAsync(string path, CancellationToken ct = default);
+}