Support disabling Webservice, Sidekiq, and/or Migrations

Summary

Closes #408 (closed)

• Adds some xyzIfEnabled helper methods to simplify logic (reducing calls to <Component>Enabled).

• Extends the isUpgrade logic as follows:

  • if upgrade
    • if migrations
      • if webservice || sidekiq
        • do upgrade logic, skipping disabled deployments
      • else
        • just run all migrations
    • else
      • reconcile enabled deployments
  • else
    • if migrations
      • run all migrations
    • reconcile enabled deployments

Testing

I tested by doing the following:

1. Deploy with spec.chart.version=5.2.4 and then upgrade to 5.3.0
   • Confirm that traditional upgrade logic is followed
2. Deploy with gitlab.webservice.enabled=false, and then upgrade
   • Confirm that traditional upgrade logic is followed, and that it never tries to reconcile Webservice
3. Deploy with gitlab.sidekiq.enabled=false, and then upgrade
   • Confirm that traditional upgrade logic is followed, and that it never tries to reconcile Sidekiq
4. Deploy with gitlab.{webservice,sidekiq}.enabled=false, and then upgrade
   • Confirm that all migrations run together, and that it never tries to reconcile Sidekiq or Webservice
5. Deploy with gitlab.migrations.enabled=false, and then upgrade
   • Confirm that migrations are skipped, and Sidekiq and/or Webservice are reconciled if enabled