FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/level-supports/test/cloneable.js

@@ -0,0 +1,26 @@
+'use strict'
+
+var supports = require('..')
+
+// Every object in a manifest must have a unique identity, to avoid accidental
+// mutation. In supports() we only shallowly clone the manifest object itself
+// and additionalMethods. If in the future we add more objects to manifests,
+// this test will break and we'll know to start performing a deep clone.
+module.exports = function cloneable (t, manifest) {
+  var copy = supports(manifest)
+  verifyUnique(t, 'manifest', manifest, copy)
+}
+
+function verifyUnique (t, path, a, b) {
+  if (isObject(a) && isObject(b)) {
+    t.ok(a !== b, path + ' has unique identity')
+
+    Object.keys(a).forEach(function (key) {
+      verifyUnique(t, path + '.' + key, a[key], b[key])
+    })
+  }
+}
+
+function isObject (o) {
+  return typeof o === 'object' && o !== null
+}