CryptoPkg/BaseCryptLib: add crypto algorithms needed by variable protection

CryptoPkg/BaseCryptLib: add crypto algorithms needed by variable protection

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2594

Crypto algorithms, hkdf-sha256/hmac-sha256/aes, are needed to verify
integrity of variable data, derive hmac and encryption keys, and
encrypt/decrypt varible. Replacing null version source code with real
implementations makes sure we can enable full functionalities of protected
variable later.

Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Guomin Jiang <guomin.jiang@intel.com>
Cc: Nishant C Mistry <nishant.c.mistry@intel.com>
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>