Implement TPM 1.2 EK flow

[Chounoki]

No description provided.

[gemini-code-assist]

Code Review

This pull request implements the TPM 1.2 EK challenge flow, introducing the TPMAsymCAContents structure and the necessary logic for challenge generation and verification. The changes also include transitioning to constant-time comparisons for sensitive data and updating gRPC error codes to better reflect state-related failures. Critical feedback identified the use of non-existent functions binary.Encode and binary.Decode, which must be replaced with binary.Write and binary.Read, respectively. Consequently, the bytes package needs to be re-imported to support these operations.