OvmfPkg/AmdSev: add BlobVerifierLibSevHashes

OvmfPkg/AmdSev: add BlobVerifierLibSevHashes

Add an implementation for BlobVerifierLib that locates the SEV hashes
table and verifies that the calculated hashes of the kernel, initrd, and
cmdline blobs indeed match the expected hashes stated in the hashes
table.

If there's a missing hash or a hash mismatch then EFI_ACCESS_DENIED is
returned which will cause a failure to load a kernel image.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3457
Co-developed-by: James Bottomley <jejb@linux.ibm.com>
Signed-off-by: James Bottomley <jejb@linux.ibm.com>
Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
[ardb: add CryptoPkg to accepted dependencies list for CI]