Zip decompression for my own Unity plugin

I am developing a Unity plugin, and as a part of 3D processing pipeline it needs to do ZIP compression and decompression. Target platforms are Win, Mac, iOS and Android.

I know that there are various Asset Store plugins for zipping/unzipping, I tested them and they worked all right. But as far as I can tell from EULA I cannot use other plugin code in my own plugin, nor can I somehow declare "dependency" on another plugin.

Does that mean that I need to develop ZIP functionality myself, even though it is not the main goal of my plugin? (ok, I can probably do that with some opensource code, but still)

More general question: are there any plans to introduce a dependency manager for Unity, like PIP or iOS PODs or NuGet, etc.? So that I could declare dependencies on ZIP library, OAuth, encryption library, and start working right away instead of developing everything from scratch.