WIP: Qt static packaging fixes for Debian

[oskirby]

Description

I am running through a variety of Debian-based distributions and assembling bug fixes as necessary to get the the statically-linked VPN client working.

Reference

Github issue #6646 (VPN-4585) Initial PR #6611

Checklist

• [ ] My code follows the style guidelines for this project
• [ ] I have not added any packages that contain high risk or unknown licenses (GPL, LGPL, MPL, etc. consult with DevOps if in question)
• [ ] I have performed a self review of my own code
• [ ] I have commented my code PARTICULARLY in hard to understand areas
• [ ] I have added thorough tests where needed

[oskirby]

Bah! Humbug! This almost worked, but then it turned into a dependency nightmare around glib. Maybe we should write our own version of libsecret but with QDbus to eliminate this dependency entirely.

[oskirby]

Well, that got things a little closer by using the system glib during building, but now we need to figure out a solution for OpenSSL, libsecret and libcap

[oskirby]

Closing this and re-opening it as #9360 to tidy up the history.