transloadit: propagate error details when creating Assembly fails (#3794)
transloadit: propagate error details when creating Assembly fails (#3794)

* transloadit: propagate error details when creating Assembly fails

Clients are expected to use `error.assembly` to inspect details about
failed Assemblies, but then we do need to always give that property
back.

I think we should have a test for this but not sure how to approach it,
since it depends on responses from the Transloadit API. I guess we'd
require a new e2e test for it?

* Apply suggestions from code review

Co-authored-by: Antoine du Hamel <909ee02df244fa319d81ef82a21a6e95e36e96a4@gmail.com>

Co-authored-by: Antoine du Hamel <909ee02df244fa319d81ef82a21a6e95e36e96a4@gmail.com>
transloadit/uppy,transloadit/uppy,transloadit/uppy,transloadit/uppy