Add options for unassigning and ward transfers

[charludo]

Short description

If you click the "Transfer" or "Assign" buttons, you will now see some additional options in the top bar, namely completely unassigning the patient (i.e. they are not discharged, but don't occupy a bed anymore) and a dropdown for moving the patient to a different ward (this will also unassign them, but also set the "recommended ward", so the patient won't be shown in the current ward's unassigned list any longer).

Proposed changes

• implement functionality as described above
• removed a bit of javascript that was handling assignment, this is instead done by simple HTML forms now, since I felt that this was a bit more robust

Side effects

Resolved issues

Fixes: #19, #80

[charludo]

The only improvement I could think of is to remove the "Unassign" button if the patient is already unassigned. But it is also fine the way it is currently.

Oh, right! Good catch, thanks. Hiding the button in that case what just one if block in the template, so I'm going to take the liberty of merging without a re-review 😅