feat(testing): add check_isardvdi_works.sh
feat(testing): add check_isardvdi_works.sh

This script is used to check if a IsardVDI installation works correctly.
Right now it tests:

- Login
- Start a desktop
- Stop a desktop
- SPICE viewer
- RDP viewer
- VPN connection (both the client and the desktops!)

isard-vdi/isard,isard-vdi/isard,isard-vdi/isard,isard-vdi/isard,isard-vdi/isard