Export PreviousUpload type

[shubham-padia]

Is your feature request related to a problem? Please describe.
When implementing a custom UrlStorage class, I had to copy-paste the PreviousUpload type here.

Describe the solution you'd like
It would be good to have the type exported so that there is no need for copy and paste.

Describe alternatives you've considered
N.A.

Can you provide help with implementing this feature?
Yes

Additional context
None

[Acconut]

Valid point, thanks for bringing this up! I agree that this type should be exported. Looking at our index.d.ts, most definitions in there should probably be exported.

Would you be willing to open a PR for this?