Move CSharpCodeMatcher to a new project (#548)

* matcher

* wip

* fix

* <VersionPrefix>1.4.0</VersionPrefix>

* .

* x

* ?

* netstandard2.1

* {}

* test

* Fix: Assembly with same name is already loaded

* _format file

* AssemblyFile = $"WireMock.CodeHelper.Class{Guid.NewGuid()}"

* AssemblyFile = $"WireMock.CodeHelper.Class{Guid.NewGuid().ToString().Replace("-", "")}"

* GC

* x

* remove load ex

* ret

* readme

* no GC

* GetImplementationTypeByInterface

* ``

* PluginLoader

* type

src/WireMock.Net/Plugin/PluginLoader.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Concurrent;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+
+namespace WireMock.Plugin
+{
+    internal static class PluginLoader
+    {
+        private static readonly ConcurrentDictionary<Type, Type> Assemblies = new ConcurrentDictionary<Type, Type>();
+
+        public static T Load<T>(params object[] args) where T : class
+        {
+            var foundType = Assemblies.GetOrAdd(typeof(T), (type) =>
+            {
+                var files = Directory.GetFiles(Directory.GetCurrentDirectory(), "*.dll");
+
+                Type pluginType = null;
+                foreach (var file in files)
+                {
+                    try
+                    {
+                        var assembly = Assembly.Load(new AssemblyName
+                        {
+                            Name = Path.GetFileNameWithoutExtension(file)
+                        });
+
+                        pluginType = GetImplementationTypeByInterface<T>(assembly);
+                        if (pluginType != null)
+                        {
+                            break;
+                        }
+                    }
+                    catch
+                    {
+                        // no-op: just try next .dll
+                    }
+                }
+
+                if (pluginType != null)
+                {
+                    return pluginType;
+                }
+
+                throw new DllNotFoundException($"No dll found which implements type '{type}'");
+            });
+
+            return (T)Activator.CreateInstance(foundType, args);
+        }
+
+        private static Type GetImplementationTypeByInterface<T>(Assembly assembly)
+        {
+            return assembly.GetTypes().FirstOrDefault(t => typeof(T).IsAssignableFrom(t) && !t.GetTypeInfo().IsInterface);
+        }
+    }
+}