R1:012af00731fd

Improve formality of "HarbormasterBuild" states

Summary:
Ref T13072. Currently, Builds have basic states (like "passed" and "failed") and pending states where a command has been issued but not yet executed (pausing, resuming, restarting, and aborting).

These are handled in a bit of an ad-hoc way, and not everything treats them the same way. In particular, the build page can concurrently report a build as "Aborting" and "Pausing", with different icons and colors.

Make everything use the same logic so…