Async upload

[KDederichs]

Feature Request

A way to upload the files asynchronously would be super helpful.

I'm running into the issue where I'm using Vich in combination with Flysystem and Hetzner S3 storage and sometimes their bucket just times out.
This then results in an error and all sorts of other issues.

If there was a way to asynchronously upload the files via Messenger one could easily retry the file upload without having to worry about it.

Q	A
New Feature	yes
RFC	no
BC Break	no

[garak]

The Messenger works with serialisation, and UploadedFile cannot be serialised.
I guess that the only way is to temporarily store your file elsewhere, saving a reference to it, and serialise it.
Then, when you consume your queue, you can send it to your external storage.

[KDederichs]

yeah it'd need to be stored locally first.
Optimally the uploadable entity would retain a reference to the local file first and when it's been moved to the final destination that reference would update.
That way you could use it as you do now without caring where the file is.

I mean I could implement something like that for my project but it'd be neat if the bundle could do it out of the box since I'm probably not the only one with that issue?

[garak]

If you find a way to generalise your implementation, feel free to propose a PR