Use distrobox instead of deb packages to install Signal Desktop

https://distrobox.it/#quick-start

Better isolation, installation of Signal on a Debian/Fedora podman container

• handle Torsocks
• change container storage driver from 'overlay' to 'vfs', check disk write speed

It's a better solution than Flatpak:

• it is not officially maintained, needs to trust random community people
• 1.6Go needed, don't working so much with bad internet connection
• isolation of $HOME not enough
• pipewire not working: audio messages impossible to listen