RHP3 Renew: Remove renter prepaying host and extend testing

MERGE REQUEST

MR Guidelines

Overview

Initially we added support for the renter to prepay the host using the final revision of the contract to be renewed. That means the renter could improve their liquidity by making the locked away money available in the next contract.

Unfortunately this raised some security concerns so we are removing it again.

Checklist

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

• All new methods or updated methods have clear docstrings
• Testing added or updated for new methods
• Any new packages are added to Makefile and .gitlab-ci.yml
• API documentation updated for API updates
• Module README.md updated for changes to workflow
• Issue added to Sia-UI repo for new supporting features
• Changelog File Created

Issues Closed