refactor(redis-v5): Move 'redis:upgrade' to CLI

[eablack]

Description

https://gus.lightning.force.com/lightning/r/ADM_Work__c/a07EE00001axUyLYAU/view

This converts redis:upgrade to oclif and updates its associated tests.

Testing

So this is a little tough because to test the successful case, you need an older version of Redis, which you can't have on a newly created addon install. The best I could do is just try to upgrade with a redis that is already at the newest version and compare with the production equivalent.

1. Run ./bin/run redis:upgrade -a APP with this branch pulled down with an app that has redis on it to update its version
2. Verify the command updates the policy by running heroku redis:info -a APP
3. Compare the results with prod cli command and make sure things look 👍