Elliptic curves: Support of spki_compressed and raw_compressed key export/import formats

[olegbespalov]

What?

During the initial implementation of the support of spki and raw formats for crypto keys import/export, the compressed formats were considered out of the scope since golang's implementation doesn't support compressed formats out of the box.

So we even have the patch to the web platform test
https://github.com/grafana/xk6-webcrypto/blob/main/webcrypto/tests/wpt-patches/WebCryptoAPI__import_export__ec_importKey.https.any.js.patch

So we need to implement support of these compression formats.

Why?

Still, they are part of the WebCrypto API and the implementation should support them.