PDP - aggregate retrieval of pieces(roots)

[jennijuju]

Checklist

• This is not a new feature or an enhancement to the Filecoin protocol. If it is, please open an FIP issue.
• This is not brainstorming ideas. If you have an idea you'd like to discuss, please open a new discussion on the Curio forum and select the category as Ideas.
• I have a specific, actionable, and well motivated feature request to propose.

Curio component

• PoRep Pipeline
• Snap Deals
• Market
• IPNI provider
• Curio UI
• Other

What is the motivation behind this feature request? Is your feature request related to a problem? Please describe.

As described in #466, it would be great if a user can request a piece with any size to be added to a pdp proof set & retrieve the whole piece/subpiece as they need.

Describe the solution you'd like

under the current status quo, one nice middle point could be curio allows retrieval of aggregated pieces/pdpp roots directly from the curio http server.

In this case, say even user has to do chuck a 450 gib piece in to multiple roots, but when they retrieve the data, they can send one request and get all the relevant roots streamed from the curio http server.

Describe alternatives you've considered

No response

Additional context

No response