Auto archive items older than 90 days

[michellejli77]

Description

Motivation/Context: In order to decrease the number of items stored in our database, we want to automatically archive items that have been on the page for more than 90 days.

• Create a helper async function to find all active items older than 90 days (added to DB over 90 days ago) and archive them
• Create a cron job that runs this function once a week

Closes #177

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Check that the cron job automatically runs by logging calls on console
• Confirm that cron scheduler is calling the auto archive function
• Check that all active items older than 90 days are moved to archive
• Check that all active items younger than 90 days are not impacted
• Check that the "Archiver" dropdown says "Automatically Archived on ..."

Test Configuration:

• Node.js version: 14.18.0
• Desktop/Mobile: Desktop
• Browser: Chrome

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes