Plugins: Add PostProcessMetadata hook

Il2CppInspector.Common/Plugins/PluginHooks.cs

@@ -0,0 +1,17 @@
+/*
+    Copyright 2020 Katy Coe - http://www.djkaty.com - https://github.com/djkaty
+
+    All rights reserved.
+*/
+
+// This is the ONLY line to update when the API version changes
+using Il2CppInspector.PluginAPI.V100;
+
+namespace Il2CppInspector
+{
+    // Hooks we provide to plugins which can choose whether or not to provide implementations
+    internal static class PluginHooks
+    {
+        public static void PostProcessMetadata(Metadata metadata) => PluginManager.Try<IPostProcessMetadata>(p => p.PostProcessMetadata(metadata));
+    }
+}