upload Files
Upload a list of files with a specific RainbowFileViewer
This method accepts as parameter a unique identifier which allows to find the current upload via the method getCurrentUploadsByIdentifier It is also possible to specify a maximum resolution for the images, by default, the maximum size of an image will be a square of side 2048 pixels with scale type = FIT_CENTER If the file descriptors are already uploaded and the viewer is specified, it is simply added to the viewer list
Parameters
List<RainbowFileDescriptor> the files to upload
RainbowFileViewer an optional viewer, if none is specified, the files are uploaded to the personal storage space
String a unique identifier that allows to retrieve the upload
Int an optional maximum size for the images
RainbowListener, Map