automactc lacks support for High Sierra+ login items

[dspruell]

macOS High Sierra migrated Login Items (some of which are exposed in the Users & Groups preferences UI) in a new location/format as described in the Objective-See blog:

2018-07-23 https://objective-see.org/blog/blog_0x31.html

automactc supports the older file (com.apple.loginitems.plist), but not this new jazz.

The location of this data is ~/Library/Application Support/com.apple.backgroundtaskmanagementagent/backgrounditems.btm.

The file is still a binary plist, although it has also undergone a change in that data is stored in Apple's "Bookmark" format. It seems that bookmark.py may implement a parser for this. Alternatively, this project also implements a parser for the file.