m-lua-scripting: wrap every script in a WpPlugin and expose async activation api

This allows scripts to declare when they have finished their loading,
so we can now also know when wireplumber is done loading and ready to
handle clients

Related to !313

modules/module-lua-scripting/script.h

@@ -0,0 +1,22 @@
+/* WirePlumber
+ *
+ * Copyright © 2022 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef __MODULE_LUA_SCRIPTING_SCRIPT_H__
+#define __MODULE_LUA_SCRIPTING_SCRIPT_H__
+
+#include <wp/wp.h>
+#include <wplua/wplua.h>
+
+G_BEGIN_DECLS
+
+#define WP_TYPE_LUA_SCRIPT (wp_lua_script_get_type ())
+G_DECLARE_FINAL_TYPE (WpLuaScript, wp_lua_script, WP, LUA_SCRIPT, WpPlugin)
+
+G_END_DECLS
+
+#endif