[FEATURE] Blocklist initial implementation

[prajjwalkumar17]

Feature Description:

This feature provides merchants with the ability to customize their transaction controls based on specific criteria. Merchants can tailor the blocklist according to their preferences, blocking the following elements as needed:
Card Numbers
Card ISINs
Extended BINs

Understanding Blocklist:
In the realm of payment processing, a blocklist serves as a security feature empowering merchants to restrict specific identifiers associated with payment methods or block certain card BINs. A fingerprint, a unique identifier linked to a payment method, and a card BIN, encompassing the first six digits of a credit card number, are key components. An extended card BIN covers the first eight digits.

Testing

Refer to the attached postman collection for the API contracts for the blocklist APIs. Currently we support blocking three types of resources i.e. card numbers (payment intrument), card bin, and extended card bin.
blocklist_api_postman.zip

For Card Bin and Extended Card Bin :-
1. Setup a Merchant Account and any Connector account
2. Make a payment with a certain card (ensure it succeeds)
3. Block the card's card bin or extended card bin
4. Try the payment again (should fail this time with an API response saying that the payment was blocked)

For Payment Instrument :-
1. Repeat steps 1 and 2 of previous section
2. In the payment confirm response, there will be an additional field called "fingerprint". This is the fingerprint id that can be used to block a particular payment method. Use this to block the card.
3. Try the payment again (should fail)