Helm: support for complex values

[manusa]

Description

Follow up on #2200
Requires #2402

Be able to provide through Helm values fragments complex values such as annotations or arrays.

# values.helm.yaml
annotations:
  example.org/one: one
  example.org/two: two

With a fragment such that

# deployment.yaml
metadata:
  annotations:
    ${annotations}

Can be processed by providing a Helm parameter:

// build.gradle
kubernetes {
  helm {
    parameters = [{
      name = 'annotations'
      value = '{{- toYaml .Values.annotations | nindent 4 }}'
    }]
  }
}