Support Folder Uploads

[super3]

No description provided.

[gabedealmeida]

Scope:

• Folders differ from files, so we first have to detect the difference
• Check every file name to make sure that it's a valid file
• If we come across a nested folder, we have to recurse into that folder
• If a filename is valid and it's not a folder, we then have to add it into a queue that we'll also have to build
• While files are in the queue, we'll have to also build out the functionality to allow users to cancel specific file uploads. This will also have to handle the case where a file has already been partially uploaded
• Error handling functionality to deal with invalid files or network issues and provide sensible feedback to the user