Feat: Alter flask to Quart for async API serving. (#11275)

### What problem does this PR solve?

#11277

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/utils/web_utils.py

@@ -23,7 +23,7 @@ from urllib.parse import urlparse
 
 from api.apps import smtp_mail_server
 from flask_mail import Message
-from flask import render_template_string
+from quart import render_template_string
 from api.utils.email_templates import EMAIL_TEMPLATES
 from selenium import webdriver
 from selenium.common.exceptions import TimeoutException