refactor(utils): improve TasStorage implementation and tests

- Change exception type from ArgumentOutOfRangeException to ArgumentException
- Fix node seeking logic by correcting candidate order
- Update Visit, Insert, and Remove methods with proper range checks
- Enhance cursor management after removal operations
- Add comprehensive test cases for edge scenarios
- Introduce AssertExtension for better exception testing
- Handle empty collection states more robustly

BallanceTasEditorTests/AssertExtension.cs

@@ -0,0 +1,28 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace BallanceTasEditorTests {
+    public static class AssertExtension {
+        public static T ThrowsDerivedException<T>(Action action) where T : Exception {
+            try {
+                action();
+            } catch (T ex) {
+                return ex;
+            } catch (Exception ex) {
+                if (ex is T derivedEx)
+                    return derivedEx;
+
+                throw new AssertFailedException(
+                    $"Expected exception of type {typeof(T)} or derived type, but got {ex.GetType()}. " +
+                    $"Message: {ex.Message}");
+            }
+
+            throw new AssertFailedException(
+                $"Expected exception of type {typeof(T)} or derived type, but no exception was thrown.");
+        }
+    }
+}