fix(cert): add slot_pubkey when verifying satscard signature

[notmandatory]

Description

fixes #42

Fixed Certificate::verify_card_signature by including the slot pubkey in the message digest when verifying a SatsCard.

Fixed Certificate::check_certificate by changing the pubkey hash used in cert chain verification to use pubkey.serialize instead of pubkey.serialize_uncompressed.

Notes to the reviewers

I tested these changes with my TapSigner, SatsCard, and SatsChip cards and they all verify now.

Changelog notice

• Fix certificate chain verification.

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

Bugfixes:

• This pull request breaks the existing API
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR