Add upibankvalidator for UPI payment address resolution

[leovarmak]

@qurbat maybe you can use this API to fetch the registered names of all the UPI

https://upibankvalidator.com/

[qurbat]

Thank you for filing this issue! I think it would be useful to implement this as a fallback provider. I'll keep you updated.

[leovarmak]

@qurbat i think we should make this the primary provider. This doesn't need api key thus simplifies it much more for the users using project.

[srikanthlogic]

Ideally - API providers must be a configuration option - and its upto users to chose which one they would want to use.

[qurbat]

I agree with @srikanthlogic on this.

The API provider should be based on user choice. While I see value in and will be implementing upibankvalidator as an API provider, I will leave it as a secondary option at the moment. My reasoning is:

1. the domain for the project was registered last month,
2. the API documentation is limited,
3. no information about their terms of service, privacy policy are available, and
4. details about the maintainer(s) of the project are not available anywhere on the website.

Given the above concerns, it may be possible that the maintainer(s) of the website, while providing a functional service, could use the data collected from queries for malicious, or more simply for non-ethical purposes. An example scenario: building a parallel database collating successful queries made with their API.

Increased documentation of their project would help with accountability, however, given that no information about the maintainer(s) of the website is currently available, and that the homepage of the project is currently essentially a mimic of the landing page of several, for the lack of a better word, "shady" API projects, I am not convinced that upibankvalidator will be a good, reliable contender for the default API provider used for upi-recon.

In any case, I will keep this issue open, as I will be making a PR soon introducing support for the upibankvalidator API. I believe it will benefit users that are for some reason unable (or unwilling) to use the API provided by Razorpay. Separately, I will also be implementing a few other API providers, however, their APIs require some more work to implement, so I will introduce a separate issue or them.

Thank you for the issue. I will keep you updated on the PR @leovarmak =)