cleanup: remove `results` collection usage, use `job_status` for results instead

[rugeli]

What needs to happen?

As part of the firebase database restructuring effort, we're consolidating result tracking into the job_status collection and deprecating results collection

When does this need to get done?

• remove results collection related code
• fetch outputs from job_status, remove redundant functions, like getOutputsDirectory( )
• other maintenance/refactors