Add native support for toolbox containers

[Jacalz]

As a step forward even from issues like #11473, it would be amazing if Zed could integrate natively with toolbx containers running on Fedora and other Linux systems. These containers are (mostly) seamlessly integrated into the desktop environment and essential for having one or more development environments available on atomic desktops like Fedora Silverblue where the root file system is read only. The big benefit over just connecting to a Podman container directly is how well integrated they are with the host. It is basically an extension of the host computer where you can install packages, and graphical applications, as usual but as a regular user. Shells, X11 and Wayland settings, home directories and all of that is passed through so it feels just like a regular installation.

I’ve personally tried a lot of setups on Fedora Silverblue to try and set up a good development environment. Visual Studio Code with dev containers never quite seem to integrate well enough with my toolboxes and there is generally both complicated setup required (something I have never quite gotten working perfectly) and various paper cuts even if you can manage to get it working.

My current setup is to have VSCodium installed inside my main toolbx container and have a desktop file run a command to start the application from within there. It has its own set of problems (mostly icons not integrating well in Gnome) but I know that it always picks up the correct development environment. I would ideally want my IDE installed as a Flatpak and connect it to the toolbox instead. If Zed can support this, I would not only ditch VSCodium with hesitation (Zed really is looking like a solid alternative already even if I install it inside the toolbox in the same way), but also be able to recommend Fedora atomic desktops to other developers.