Update the attestation report to v3

[vele-lorica]

Hi everyone, are there any plans to update the attestation report version to v3 from v2? In the following new spec from Oct. 2024, the version has updated to v3.

https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/programmer-references/56860.pdf

[DGonzalezVillal]

We do intend to patch it, but we have been discussing on what would be the best way to approach this issue, since there is an interest to keep some semblance of backwards compatibility.

This is a draft PR of one of the possible solutions: #268

Feel free to share your thoughts