feat: Optional proxy autentication (#2143)

example.js

@@ -2,7 +2,11 @@ const { Client, Location, List, Buttons, LocalAuth } = require('./index');
 
 const client = new Client({
     authStrategy: new LocalAuth(),
-    puppeteer: { headless: false }
+    // proxyAuthentication: { username: 'username', password: 'password' },
+    puppeteer: { 
+        // args: ['--proxy-server=proxy-server-that-requires-authentication.example.com'],
+        headless: false
+    }
 });
 
 client.initialize();