Split siatests into 2 runners

MERGE REQUEST

Overview

This MR splits the siatests into 2 runners to speed up the online CI and adds missed packages. There will now be a general siatest-tests runner and a siatest-renter-tests since the renter has the most siatests currently. This structure also allows us in the future to split out additional packages as they start growing to the size of the renter.

To help with the renter tests not timing out, I moved the hostdb_test.go and contractor_test.go files to their own sub packages of siatest/renter to match the modules structure and to move those tests into their own timeout limits.

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.

• 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