shows all tapes with the relevant info
* which pool it belongs to
* what backups are on it
* which media-set
* location
* etc.
This is very rough, and maybe not the best way to display this information.
It may make sense to reverse the tree, i.e. having pools at top-level,
then media-sets, then tapes, then snapshots..
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
