As an author, I want to be able to upload multiple assets via drag & drop to a chooser dialog, so that I can upload multiple assets quickly 

ACs

• When in an empty state, the footer is also empty (no buttons)
• CTAs (buttons, interactions) on the screen are implemented
  • Skip the clear all button
• When loading the assets, the 'Upload button' becomes disabled until the loading is completed
  • all items in the files backlog are ready to be saved in jcr 
• The footer dynamically shows the number of selected items and the visibility of buttons
• When the assets are uploaded, they need to be selected in the browser view
• Disable the Upload button when there are files in progress

Screen mockups