"Check Prereqs Only" behavior not working as intended

[thebleucheese]

When using the "Check Prereqs Only" button the system should run only the prerequisites and return results. MACAT should allow users to then rerun prerequisite checks using the same button so users have an opportunity to correct issues with prereqs.

After users have finished checking prereqs, clicking the "Run Simulation" button should then skip running prerequisites and return results for only command and cleanup steps.

This behavior is currently incomplete, but is in development right now.

[thebleucheese]

I'm going to close this as good-enough for tech preview level completeness, should be released shortly. Planning to do a new build this weekend.