archive_digest: Use correct providers with Windows Crypto

archive_digest: Use correct providers with Windows Crypto

Trying to use SHA256, SHA384 or SHA512 with mtree when linked against
Windows Crypto would result in silent failure.  The call to
`CryptCreateHash` would fail with 0x80090008.  The docs[1] say that
these algorithms require a different crypto provider, so let's make
that a parameter for `win_crypto_init` and choose at the call site along
with the algorithm.

[1] https://docs.microsoft.com/en-us/windows/win32/seccrypto/alg-id

Signed-off-by: David Macek <david.macek.0@gmail.com>