WIP: Partial Uploads MR # 2: PartialChunkSet

MERGE REQUEST

Overview

This MR adds the partialchunkset plus its tests to the codebase without actually using it in the code.

Changes to Work Flow

The partialChunkSet is responsible for combining partial chunks into combined chunks. It's not connected to the repair code yet, but once it is it will be informed about partial chunks at the end of siafiles and append them to the corresponding unfinished combined chunk. It will then add some metadata to the siafile to let it know about the combined chunk it is part of.

Testing Changes

Tests within partialchunkset_test.go

Documentation Changes

Will be added after the initial review

Modules and Packages Impacted

modules/renter

Example for Visual changes (ie Screenshot)

N/A

Issues Closed

N/A

Checklist

Review and complete the checklist to ensure that the MR is complete before assigned to an approver.

• Pipeline Passing (this is for NDFs where tests were run in a loop)
• All new methods, or updating methods have clear docstrings
• Testing added or updated for new methods
• API documentation updated for API updates
• Module README.md updated for changes to work flow
• Issue added to Sia-UI repo for new supporting features