Allow passing options when using MultipartStore API

[netthier]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

I want to pass options as present in ObjectStore::put_multipart_opts to a multipart upload created via the MultipartStore interface.

Describe the solution you'd like

MultipartStore could receive a new method, maybe create_multipart_opts, taking something like PutMultipartOpts or an entirely new struct.

Annoyingly, it seems like AmazonS3 takes multipart options at creation, while MicrosoftAzure does so at completion...

Describe alternatives you've considered

Alternatively, the put_multipart API of ObjectStore could be used, but I need the ability to resume uploads after restarts, which seems to only be possible with the MultipartStore API which provides me with a MultipartId I can persist.

[tustvold]

Annoyingly, it seems like AmazonS3 takes multipart options at creation, while MicrosoftAzure does so at completion...

Yup this is the thing that makes this hard 😅

I think adding resume support to put_multipart might be more tractable tbh