[feature request] Add reservation end date in kiosk to enable overnight reservation

[r-xyz]

Hi,
It could be useful to enable the possibility to book an equipment from the kiosk overnight.

It would require to add a new field in NEMO/apps/kiosk/templats/kiosk/tool_reservation.html and modify `NEMO/apps/kiosk/view.py#reserve_tool.

Would a PR be accepted?
If so, could it be enabled by default? I was thinking to auto-fill end_date when start_date is selected, in order not to modify default user experience (end_date=start_date).

[rptmat57]

sure. this will also required changing/fixing the unavailable_times implementation so that it works with different dates (the idea there is that we want to gray out all already reserved times)