[applications] Add Escrow-Xput Function In Bare-Metal SNP

[csegarragonz]

Closes #25

[csegarragonz]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces significant new functionality for running and attesting applications in a bare-metal AMD SEV-SNP environment. This includes a new escrow-xput application, extensive CLI tooling in accli for managing confidential VMs (cVMs) and a new attestation service, and the core logic for SNP report verification in the attestation service itself. The changes are extensive and well-structured, particularly the cVM orchestration in accli and the caching mechanisms in the attestation service.

My review focuses on a critical security gap in the SNP attestation flow, several maintainability issues in the new application code, and opportunities to improve the robustness of the new tooling. The most critical issue is the missing validation of the SNP report's measurement, which must be addressed to ensure only trusted code is attested. Other points include removing a large amount of commented-out code and improving configuration handling in the new benchmark application.