use weakmap to avoid references from node to datadog stores

packages/datadog-core/src/storage.js

@@ -2,20 +2,36 @@
 
 const { AsyncLocalStorage } = require('async_hooks')
 
+class DatadogStorage {
+  constructor () {
+    this._storage = new AsyncLocalStorage()
+  }
+
+  enterWith (store) {
+    const handle = {}
+    stores.set(handle, store)
+    this._storage.enterWith(handle)
+  }
+
+  getStore () {
+    const handle = this._storage.getStore()
+    return stores.get(handle)
+  }
+}
+
 const storages = Object.create(null)
-const legacyStorage = new AsyncLocalStorage()
+const legacyStorage = new DatadogStorage()
 
 const storage = function (namespace) {
   if (!storages[namespace]) {
-    storages[namespace] = new AsyncLocalStorage()
+    storages[namespace] = new DatadogStorage()
   }
   return storages[namespace]
 }
 
-storage.disable = legacyStorage.disable.bind(legacyStorage)
 storage.enterWith = legacyStorage.enterWith.bind(legacyStorage)
-storage.exit = legacyStorage.exit.bind(legacyStorage)
 storage.getStore = legacyStorage.getStore.bind(legacyStorage)
-storage.run = legacyStorage.run.bind(legacyStorage)
+
+const stores = new WeakMap()
 
 module.exports = storage