Batch Unmount

As a user I want to have the option to unmount multiple devices/platforms in one batch. Idea is to have a wizzard similar to the mount process (see https://gitlab.hzdr.de/hub-terra/sms/frontend/-/issues/268)

Acceptance criteria

button to reach the batch unmount functionality from the configurations platform & devices page
select the devices/platforms
insert the unmount date, contact & description (unclear if before or after the selection of the devices/platforms)
validate that we don't unmount a platform that still has childs left
valdiate that we don't umount a device that is still needed for the dynamic location
show actions before submit
possibility to unmount both platforms & devices in one batch