Add additional use cases to 3.x to 4.x migration script

General MR

Summary

• Users typically SOPS encrypt values with sensitive credentials using a k8s Secret template. The Migration script needed the ability to accept a values file inline in a K8s Secret yaml template. This MR provides that with an additional optional script that can sops decrypt a secret and invoke the migration script to follow.
• This MR also updates the ADR 11 and blog to reflect our decision that users can run the migration script now but will need to re run the script prior to the 4.0 release. Additional changes are being completed that will require changes to the migration script. BB-common changes were deferred to the final 3.x release so the migration script will ship in two phases.
• Updated the migration script to preserve ordering of packages to reduce the review burden of the changes

Relevant logs/screenshots

N/A

Linked Issue

Closes #3455 (closed)

Upgrade Notices

Big Bang 3.x to 4.x migration script now includes the functionality to migrate decrypted values in a K8s Secret