Setting Find Changes

- added a find window to find setting in the settings control.

src/ServerManager.Common/Extensions/StringExtensions.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace ServerManagerTool.Common.Extensions
+{
+    public static class StringExtensions
+    {
+        public static bool Contains(this string value, string substring, StringComparison comparisonType)
+        {
+            if (substring == null)
+                throw new ArgumentNullException(nameof(substring), $"{nameof(substring)} cannot be null.");
+            if (!Enum.IsDefined(typeof(StringComparison), comparisonType))
+                throw new ArgumentException($"{nameof(comparisonType)} is not a member of StringComparison", nameof(comparisonType));
+
+            return value.IndexOf(substring, comparisonType) >= 0;
+        }
+    }
+}