ER: Mark keychain item as kSecAttrSynchronizable for use with iCloud Keychain

Currently, all NoMAD passwords are not marked as being able to by synchronized via iCloud.

changed milestone to %V. 1.1

On further digging, this will most likely require adding entitlements to the app. Moving to 1.1.

If this feature makes it into the wild i would really like a preference key for it. This is not a feature i would use. Its more a feature i would forcefully disable.

This would certainly be opt-in and overridable by a configuration profile.

The current investigation that we've done into this shows that it will be more work than we first thought. As such it'll probably be a while before we put this in regardless.