RPC: Update by sector root

MERGE REQUEST

Overview

This MR adds a new RPC which allows for updating sectors by providing the root of the sector, an offset and some data.

Testing Changes

TestModifySectorByRoot

Documentation Changes

N/A

Modules and Packages Impacted

modules/host, modules/renter/proto, modules, siatest/renterhost

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