Update the OpenApiPathsMapper to handle Value/Wildcard (#691)

src/WireMock.Net.OpenApiParser/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,21 @@
+#if NET46 || NETSTANDARD2_0
+using System.Collections.Generic;
+
+namespace WireMock.Net.OpenApiParser.Extensions
+{
+    internal static class DictionaryExtensions
+    {
+        public static bool TryAdd<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key, TValue value)
+        {
+            if (dictionary is null || dictionary.ContainsKey(key))
+            {
+                return false;
+            }
+
+            dictionary[key] = value;
+
+            return true;
+        }
+    }
+}
+#endif