Add support for changing kSecUseDataProtectionKeychain

[alex-mcleod]

This option was added in Catalina and is required if you are using Keychain access groups.

[gabriel]

I think you'd need to do this a seperate fork since this is only supported in Catalina and there are no golang build contraints for macos versions?

Also this fork could automatically enable it on new items by default as suggested by the documentation.

[idcmp]

With pre-Catalina being EOL, this should be safe to merge now? (source: https://computing.cs.cmu.edu/desktop/os-lifecycle )