- Make fingerprint and key ID computation async, and rely on Web Crypto
for hashing if available
- Always set fingerprint and keyID on key parsing / generation
- Introduce `*KeyPacket.computeFingerprint()` and
`*KeyPacket.computeFingerprintAndKeyID()`
- Change `getKeyID` and `getFingerprint*` functions to return the
pre-computed key ID and fingerprint, respectively
- Make `PublicKeyPacket.read` async