feat(helm): Allow external TLS provider for webhook

[anael-l]

closes: #407

Added a new parameter app.webhook.tls.certManager.enabled=true that keeps the default config to create certmanager certificates, but that can be disabled.

Added new parameters app.webhook.annotations and app.webhook.service.annotations to set annotations for the ValidatingWebhookConfiguration and Webhook Service respectively.

This allows for having another way to provide TLS certificates like for instance wih the Openshift service serving certificates

Example values:

app:
  webhook:
    annotations:
      service.beta.openshift.io/inject-cabundle: "true"
    service:
      annotations:
        service.beta.openshift.io/serving-cert-secret-name: '{{ include "trust-manager.name" . }}-tls'
    tls:
      helmCert:
        enabled: false
      certManager:
        enabled: false

[cert-manager-prow]

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[cert-manager-prow]

Hi @anael-l. Thanks for your PR.

I'm waiting for a cert-manager member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[erikgb]

This appears like a breaking change. Is it intentional? If possible, I think we should still support the app.webhook.tls.helmCert.enabled Helm value.

[anael-l]

the app.webhook.tls.helmCert.enabled still works, but for for existing installation, the app.webhook.tls.certManager.enabled var would have to be set to false, which indeed is a breaking change.

Should we have instead a app.webhook.tls.externalProvider.enabled=false var that when enabled, disables the cert-manager certficates creation ?

[erikgb]

I am not sure if this will work, but could it be an option to add a new optional Helm value to set the name of the webhook certificate secret? And when user sets this value, all use of cert-manager or Helm to generate a webhook certificate is turned off?