feat: ability to run arbitrary sidecar extraContainers

[joshuasimon-taulia]

adds the ability to run arbitrary sidecar extraContainers

i have a use case where i need to use cloudsql proxy to connect the pact broker to a google cloudsql postgres instance.

extraContainers:
  - name: cloudsql-proxy
    image: gcr.io/cloudsql-docker/gce-proxy:1.22.0
    command:
      - /cloud_sql_proxy
      - '-instances=my-project:my-zone:my-db-name=tcp:5432'
      - '-enable_iam_login'

another common use cases is running a vault sidecar to inject secrets

test values correctly output a new sidecar

        - command:
          - /cloud_sql_proxy
          - -instances=my-project:my-zone:my-db-name=tcp:5432
          - -enable_iam_login
          image: gcr.io/cloudsql-docker/gce-proxy:1.22.0
          name: cloudsql-proxy

mostly copied from the common pattern at https://github.com/argoproj/argo-helm/blob/c08fc230d75c85b2c9a07138c5c7b7bc957b98df/charts/argo-cd/templates/argocd-repo-server/deployment.yaml

[joshuasimon-taulia]

@ChrisJBurns fiddling with PGP to get my commits verified autoclosed and bugged out #46.

[ChrisJBurns]

@joshuasimon-taulia Will you be able to rebase your branch with master? When you've done this, we can get this merged in. Also could you update the issue description so it doesn't have the database password issue as this has been fixed with #43

[joshuasimon-taulia]

@joshuasimon-taulia Will you be able to rebase your branch with master? When you've done this, we can get this merged in. Also could you update the issue description so it doesn't have the database password issue as this has been fixed with #43

done and confirmed working

[joshuasimon-taulia]

thx!