API for custom file upload behaviour / Extending built-in internals#637

Object storage providers like S3 use pre-signed URLs to upload directly to the buckets and bypass the server which usually has upload restrictions.

In Kirby 3, this plugin could extend the built-in upload Vue component:
https://github.com/dgtl-one/kirby-chunky

Since Kirby 4, all file uploading has been switch to the upload internal in global scope. This could be replaced (in the global scope), but unsure if they’re any side effects to that.

It’d be great if there was an official API provided that allows you to extend the Upload internals similiar to how you can extend Vue components.