Closes: #48
This PR should allow the user to upload an image that has been taken with the camera and the associated detection information to a file server. These file can then be used to add data to ALVINN's models.
Current upload destination is set to a file drop folder in Georgi Lab Nextcloud, but eventually (maybe) should be changed to some dedicated ALVINN backend.
Also, prediction data is still not formatted in any specific way. It is just a JSON array of (top, left, bottom, right, label) objects.
Reviewed-on: Georgi_Lab/ALVINN_f7#56
