Testing: tracking issue: improvements

[bgins]

Summary

This issue is a tracking issue for testing improvements. Each of these items could be separated out into individual sets of work.

Tasks

• Add Homestar command builder test utility for starting a Homestar node with default environment settings, including RUST_BACKTRACE=0. The builder should have an option for piping stdout or not to test support test development.
• Break up homestar-runtime/tests/utils.rs into smaller modules