Eduvpn-client

This pre-release are a couple of Let's Connect! and threading changes

* Try to fix threading issues by only running async nm functions in the glib thread
* Fix launching of Let's Connect!
* Properly hide certain elements that are only applicable for eduVPN

This pre-release are a couple of QoL changes in the UI

* Do not style tree views
* Remove settings & help page and create an info popup instead
* Remove cancel on right click on a server
* Add dark theme support by using the right icons and using default buttons when we can
* Improve failover UI
* Add additonal logging to keyring

This pre-release refactors the whole app using the [eduvpn-common](https://github.com/eduvpn/eduvpn-common) Go library.

Fixes
* 481 - The OAuth library/implementation we use now is built in house and fixes this
* 478/465 - A profile expander is shown now
* 467 - The CLI has been rewritten to be more user friendly and work correctly with the V3 API
* 453 - Back buttons are shown correctly where they are possible/needed
* 434 - Most tests are now in the Go library that sets up a local network
* 428 - Proper imeouts are now used
* 426 - A renew session button is shown with accordance to the eduVPN specification https://github.com/eduvpn/documentation/blob/v3/API.md#session-expiry
* 412 - Prehashed signatures are supported because we use the official minisign go library in the eduvpn-common codebase
* 405 - The CLI now works correctly and should be more user friendly, especially if the interactive mode is used
* 374 - Let's Connect! now also has a CLI
* 351 - No longer a warning should be shown
* 336 - Implemented
* 335 - Exceptions are now shown in an error revealer similar to other clients
* 333 - Implemented
* 255 - We now implement it according to the eduVPN specification
* 253 - Removing a connection is now possible by right clicking on a server

New features/Improvements that are not mentioned yet
* OAuth has a check for the new ISS parameter if the server supports it (https://datatracker.ietf.org/doc/rfc9207/)
* A server is now added instead of immediately connected, making it the same as other clients. The old behaviour can be toggled in the settings
* Let's Connect!/eduVPN now uses completely separate configurations
* Keyring implementation using Dbus to securely store OAuth tokens
* WireGuard to OpenVPN failover (if UDP is blocked)

Additions
* 489 Make NetworkManager connections optionally for the current user only by jwijenbergh. This can get rid of authentication popups depending on your polkit settings
* 490 Add a quick note for the AUR package by jwijenbergh

Bugfixes
* 491 Refactor selections by jwijenbergh. This fixes profiles/servers being selected automatically
* 494 Simplify getting interface/IP info and fix inconsistencies by jwijenbergh. This gives a more accurate way to get the network interface across all systems
* 495 Cleanup network states by jwijenbergh. This makes sure that we use the right connection for state updates, which fixes bugs when using eduVPN with another VPN/Connection. Additionally it fixes a major bug with reconnecting when using OpenVPN
* 497 Fix server info launch by jwijenbergh. This guarantees that server info is correctly displayed when launching the app with an active eduVPN connection