Clean up yk8 branch

[timweri]

Note: The large diff is due to the inclusion of Cargo.lock.

Followed #27 and implemented our own type which implements KeyType, allowing us to avoid importing p256 and p384. However, I used spki for signature verification instead of ring.

These tests work on:

• Firmware 5.7.1 with default 3DES management keys:
• Firmware 5.7.2 with default AES192 management keys:

cargo run --example yk-provision --features yubikey-support -- \
  --slot R3 --subject "my-test-key" --type p384

cargo run --example yk-provision --features yubikey-support -- \
  --slot R3 --subject "my-test-key" --type p256

cargo run --example yk-generate-csr --features yubikey-support -- -s R3

[timweri]

@obelisk The .to_der() is incorrect. This change makes cargo run --example yk-generate-csr --features yubikey-support -- -s R3 pass.

[obelisk]

Does it cause any other use cases to fail that expected the faulty behaviour in Rustica?