Add support for phone number authentication with Khoj (part 2) (#621)

* Allow users to configure phone numbers with the Khoj server

* Integration of API endpoint for updating phone number

* Add phone number association and OTP via Twilio for users connecting to WhatsApp

- When verified, store the result as such in the KhojUser object

* Add a Whatsapp.svg for configuring phone number

* Change setup hint depending on whether the user has a number already connected or not

* Add an integrity check for the intl tel js dependency

* Customize the UI based on whether the user has verified their phone number

- Update API routes to make nomenclature for phone addition and verification more straightforward (just /config/phone, etc).
- If user has not verified, prompt them for another verification code (if verification is enabled) in the configuration page

* Use the verified filter only if the user is linked to an account with an email

* Add some basic documentation for using the WhatsApp client with Khoj

* Point help text to the docs, rather than landing page info

* Update messages on various callbacks and add link to docs page to learn more about the integration

pyproject.toml

@@ -78,6 +78,7 @@ dependencies = [
     "openai-whisper >= 20231117",
     "django-phonenumber-field == 7.3.0",
     "phonenumbers == 8.13.27",
+    "twilio == 8.11"
 ]
 dynamic = ["version"]