[chart] Allow creation of serviceMonitor in a different namespace

[jsalatiel]

Currently cert-manager chart allows to have

  prometheus:
    enabled: true
    servicemonitor:
      enabled: true
      namespace: monitoring

But serviceMonitor in trust-manager does not accept the namespace key. So

  app:
    metrics:
      service:
        servicemonitor:
          enabled: true

will always create the serviceMonitor inside the trust-manager monitor.
Please add a parameter to accept creation in another namespace.

[cert-manager-bot]

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[cert-manager-bot]

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