[FileUploader] Drag and drop support in file uploader

[asudoh]

Summary

This issue tracks dev effort for implementing drag and drop-based file uploader and possibly beefing up design spec (some if there) from carbon-design-system/carbon-contribution#4.

Justification

Drag and drop-based file uploader UI has been popular these days, often provides a better user experience than letting user choose file.

[shixiedesign]

According to comment thread, Cynthia's team will build it. Just followed up to check the status on this:
carbon-design-system/carbon-contribution#4 (comment)

[stale]

We've marked this issue as stale because there hasn't been any activity for a couple of weeks. If there's no further activity on this issue in the next three days then we'll close it. Thanks for your contributions.

[laurenmrice]

not stale?

[shixiedesign]

We should go ahead and add this to our to-do since contribution thread is 1 year old, and likely stale. We definitely want to include this feature in our core component set. Reposting spec from contribution issue:

Drag and drop file uploader spec, ready for dev 🤖(Updated Sept 3rd)

[shixiedesign]

We will look at it more next month. Here's some potential Usage tab content for Drag and Drop component once it merges. FYI @connor-leech

https://pages.github.ibm.com/ide-design-guidelines/ide-design-guidelines-v2/patterns/uploading/usage

[asudoh]

@emyarod FYI

[vikkipaterson]

I have come across this issue and see that the file upload usage pattern we submitted is referenced above in it. Is the drag drop component being created for your Aug release? Is it specced out somewhere so we can see the details as we are keen to use this component (and also the proposed usage details)
Thanks :)

[shixiedesign]

Replied in Slack. Lemme know if you have suggestions for Usage guidance!