Initial plugin runtime api implementation

packages/node_modules/@node-red/runtime/lib/plugins.js

@@ -0,0 +1,10 @@
+const registry = require("@node-red/registry");
+
+module.exports = {
+    init: function() {},
+    registerPlugin: registry.registerPlugin,
+    getPlugin: registry.getPlugin,
+    getPluginsByType: registry.getPluginsByType,
+    getPluginList: registry.getPluginList,
+    getPluginConfigs: registry.getPluginConfigs,
+}