Allows parsing X509 certificates. This is needed for verifying BIP70 PaymentRequests.
This is based on:
- https://github.com/hansekontor/checkout-components/blob/main/lib/b70/utils/asn1.js
- https://github.com/vinarmani/bitcore-payment-protocol
Names for the OID variables have been taken from https://oid-base.com/ (screaming snake case-ified). This is the reason why the OID constant of the secp256k1 curve is called OID_ANSIP256K1, because that's the official name.
Depends on D17733.