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/strip-final-newline/index.js

@@ -0,0 +1,14 @@
+export default function stripFinalNewline(input) {
+	const LF = typeof input === 'string' ? '\n' : '\n'.charCodeAt();
+	const CR = typeof input === 'string' ? '\r' : '\r'.charCodeAt();
+
+	if (input[input.length - 1] === LF) {
+		input = input.slice(0, -1);
+	}
+
+	if (input[input.length - 1] === CR) {
+		input = input.slice(0, -1);
+	}
+
+	return input;
+}