Common class for registry migration settings

🔥 Problem

The [container registry migration] has many toggles to control how the migration is done.

We have:

• many application settings
• many feature flags

Some feature flags need to be translated to actual values.

For example, we have wait durations that are set by feature flags. If the fast mode feature flag is enabled, then the wait duration should be set to 0.

🚒 Solution

Introduce a ContainerRegistry::Migration module and have class methods that will:

• alias feature flags/application settings
• "interpret" or "translate" feature flags/application settings.