Tool for making iOS 17+ RSD tunnels

It has been written to be as minimal as possible to enable the following:

1. Creating QUIC RSD tunnels for iOS 17+ devices
2. Creating TCP RSD tunnels for iOS 17.4+ devices
3. "Lockdown pairing" iOS devices
4. "Remote pairing" iOS 17+ devices
5. Doing all of the above without running any Python code as root.
6. Support iPhone XR, XS, and beyond ( iOS 17 devices )

In order to minimize the dependencies of the project a few choices have been made:

1. cryptography module is avoided outside of use of bits of it within the qh3 library being depended on. This is to avoid the large size of the library, as well as the non-standard way it works that would make it hard to port this project to C. For ECC, PyNaCL module is used.
2. oscrypto module is used. It is small and great for creating certificates, which is needed for pairing. It hasn't been done yet, but oscrypto can handle socket SSL wrapping also, which will enable the project to avoid depending on the Python SSL module, which is problematically dependent on OpenSSL, which is bad for use of this embedded in an app.
3. MDNS service discovery requests are created manually and the response parsed manually to avoid the use of the dnslib module. The dnslib module is small ( 500kb ) so this is an over-optimization. https://github.com/dryark/py_cf_mdns is used.
4. hkdf has been written in as it's tiny and pointless to use a library for it.

The utun interactivity has been rewritten to use "external utuns". An example of one way to do this is in external_utun.py

The code has been changed to suspend / resume remoted using an external c program via shell-out.

Currently the project is designed only to run on MacOS. Some additional alterations will be needed to make it run on Linux. Windows is not an intended target.