lisa._kmod: Add fuse-overlayfs overlay backend

FEATURE

Add "fuse-overlayfs" backend in addition to the existing "overlayfs".
This backend has much better performance than the "copy" backend even if
it is itself worse than the native "overlayfs". However, it can come in
handy in environments that don't allow user namespaces like some modern
distribution (e.g. Ubuntu 24.04 without specific configuration).