Add digest OID to PKCS7/SCEP digest failure logs

[stevendpclark]

Description

To help debugging in the future without requiring a full packet capture lets add the digest OID that we used to select the hashing algorithm that led to the digest mismatch

TODO only if you're a HashiCorp employee

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PCI review checklist

• I have documented a clear reason for, and description of, the change I am making.
• If applicable, I've documented a plan to revert these changes if they require more than reverting the pull request.
• If applicable, I've documented the impact of any changes to security controls.

Examples of changes to security controls include using new access control methods, adding or removing logging pipelines, etc.

[github-actions]

CI Results:
All Go tests succeeded! ✅

[github-actions]

Build Results:
All builds succeeded! ✅

[victorr]

👍