Combine File Upload and File Upload Multiple into a single component

[mcarrano]

Currently File Upload and File Upload - Multiple are separate components to address distinct use cases. A more usable solution would be to combine these into one component. File Upload Multiple supports all upload use cases excepting the ability to preview a text file. Let's look at this to see if this can be added to File Upload Multiple allowing us to deprecate the single File Upload component.

Use cases:

• Upload a single text file and give users the option to edit.
• Upload a single binary file (no preview)
• Upload multiple binary files in a single operation (no preview)
• Select file to upload either by browsing the file system or drag and drop.

[mcarrano]

@yichen1yu Thanks for taking this on. I suggest starting be using the multiple file upload as a base and thinking about how to incorporate a single file text preview as an option. @megan-hall worked on this previously and should be able to provide any addition background about earlier design decisions and/or Sketch files so you don't need to start from scratch. Let me know if you have questions.

[yichen1yu]

Here is the final design flow https://www.sketch.com/s/333bbc45-e187-4e1a-8c4e-f122ceab05ed