feat: expose the sign and verbose runtime parameters as helm variables

[rowansmithau]

Per Slack discussion this PR allows folks who deploy to Kubernetes to make use of the --verbose and --sign runtime parameters so they don't have to manually edit the template pre/post deployment.

Both are opt in and disabled by default in order to not change existing behaviour.

➜  helm git:(feat/helm_expose_sign_and_logging_params)  helm template -n code-marketplace --create-namespace code-marketplace . --set verboseLogging=true --set extensionSigning=true
....
# Source: code-marketplace/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
....
          args:
            - --address
            - "0.0.0.0:80"
            - --extensions-dir
            - /extensions
            - --verbose
            - --sign
          volumeMounts:

➜  helm git:(feat/helm_expose_sign_and_logging_params)  helm template -n code-marketplace --create-namespace code-marketplace .
....
          args:
            - --address
            - "0.0.0.0:80"
            - --extensions-dir
            - /extensions
          volumeMounts:

[code-asher]

Awesome thanks!