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/base64-js/README.md

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+base64-js
+=========
+
+`base64-js` does basic base64 encoding/decoding in pure JS.
+
+[![build status](https://secure.travis-ci.org/beatgammit/base64-js.png)](http://travis-ci.org/beatgammit/base64-js)
+
+Many browsers already have base64 encoding/decoding functionality, but it is for text data, not all-purpose binary data.
+
+Sometimes encoding/decoding binary data in the browser is useful, and that is what this module does.
+
+## install
+
+With [npm](https://npmjs.org) do:
+
+`npm install base64-js` and `var base64js = require('base64-js')`
+
+For use in web browsers do:
+
+`<script src="base64js.min.js"></script>`
+
+[Get supported base64-js with the Tidelift Subscription](https://tidelift.com/subscription/pkg/npm-base64-js?utm_source=npm-base64-js&utm_medium=referral&utm_campaign=readme)
+
+## methods
+
+`base64js` has three exposed functions, `byteLength`, `toByteArray` and `fromByteArray`, which both take a single argument.
+
+* `byteLength` - Takes a base64 string and returns length of byte array
+* `toByteArray` - Takes a base64 string and returns a byte array
+* `fromByteArray` - Takes a byte array and returns a base64 string
+
+## license
+
+MIT