spdm: Support vendor command in data phase

The vendor command is just wrapping the raw application messages the
requester is sending to the responder under the hood of spdm protocol.

BUG=b:284404632
TEST=cargo test

Change-Id: I973ca819974a03644ee4a347491708aedfdc1441
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/spdm/+/5019430
Tested-by: Howard Yang <hcyang@google.com>
Commit-Queue: Howard Yang <hcyang@google.com>
Reviewed-by: Vadim Sukhomlinov <sukhomlinov@chromium.org>
17 files changed