Add ContainsIgnoreCase helper to reduce string alloc, cleanup

src/Core/Utility/MiscUtility.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+
+namespace UnityExplorer
+{
+    public static class MiscUtility
+    {
+        private static CultureInfo _enCulture = new CultureInfo("en-US");
+
+        public static bool ContainsIgnoreCase(this string _this, string s)
+        {
+            return _enCulture.CompareInfo.IndexOf(_this, s, CompareOptions.IgnoreCase) >= 0;
+        }
+    }
+}