api-types: api: tape: add notification-mode parameter

api-types: api: tape: add notification-mode parameter

Same as with datastores, this option determines whether we send
notifications the old way (send email via sendmail to a user's email
address) or the new way (emit matchable notification events to the
notification stack).

Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>
Tested-by: Gabriel Goller <g.goller@proxmox.com>
Reviewed-by: Gabriel Goller <g.goller@proxmox.com>
Tested-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>