[draft] secp256k1 curve

[autonome]

Stds conversations

• closed request: https://github.com/w3c/webcrypto/issues/82

Browser issues

• https://bugzilla.mozilla.org/show_bug.cgi?id=1051509
• https://github.com/brave/brave-browser/issues/36015

Polyfills etc

• https://github.com/paulmillr/noble-secp256k1
• https://github.com/DimensionDev/secp256k1-webcrypto
• https://github.com/hazae41/secp256k1

WebCrypto API docs/impl

• https://developer.mozilla.org/en-US/docs/Web/API/Web_Crypto_API
• https://caniuse.com/cryptography
• On advocacy: https://github.com/w3c/webcrypto/issues/280