Windows SDDL strings vs. binary representation choice

[indrora]

Currently, we specify the security descriptor should be an SDDL string. This is apparently not
something that Microsoft particularly consider up to date, as it's considered "legacy" in the
backuptar implementation in Microsoft/go-winio.

I'm tempted to say that two versions, "sddlString" vs "sddlBinary" could exist, but what happens
when they differ? Additionally, there aren't SDDL string compilers for Go, and I don't feel like
writing one today.

[indrora]

Favor towards strings.

While they're not the cleanest, they're what Azure uses and they're readable by humans in the worst case.