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/leveldown/chained-batch.js

@@ -0,0 +1,28 @@
+const util = require('util')
+const AbstractChainedBatch = require('abstract-leveldown').AbstractChainedBatch
+const binding = require('./binding')
+
+function ChainedBatch (db) {
+  AbstractChainedBatch.call(this, db)
+  this.context = binding.batch_init(db.context)
+}
+
+ChainedBatch.prototype._put = function (key, value) {
+  binding.batch_put(this.context, key, value)
+}
+
+ChainedBatch.prototype._del = function (key) {
+  binding.batch_del(this.context, key)
+}
+
+ChainedBatch.prototype._clear = function () {
+  binding.batch_clear(this.context)
+}
+
+ChainedBatch.prototype._write = function (options, callback) {
+  binding.batch_write(this.context, options, callback)
+}
+
+util.inherits(ChainedBatch, AbstractChainedBatch)
+
+module.exports = ChainedBatch