Add support for generating SHA-256 hashes via CryptCATAdminCalcHashFromFileHandle2, which in turn requires CryptCATAdminAcquireContext2 in order to be able to specify the hashing algorithm.
-- v6: wintrust/tests: Add CryptCATAdminCalcHashFromFileHandle2() tests wintrust: Implement CryptCATAdminCalcHashFromFileHandle2() wintrust/tests: Add CryptCATAdminAcquireContext2() tests wintrust: Implement CryptCATAdminAcquireContext2()