Binary-safe md5, sha256 and hmac functions

ZBXNEXT-7616 introduced binary-safer implementation, but not the binary-safe one. There are still some characters that are causing invalid results.

For example, md5("\xb2") returns "9fc99bcc6cd99aecf306a14fd81d0eb1" while the expected result is "9941ae7962f3830b2e901dd62c0a0fc9". This is caused by the fact that "\xb2" gets converted to "\xc2\xb2".