feat(template): Check that Helm defined templates carry the chart name

[lfrancke]

Adds a script called by prek which walks our charts and checks whether all defines/calls use a namespaced name

I tested it locally:

❯ python3 scripts/check_namespaced_defines.py deploy/helm/trino-operator/templates/*
  deploy/helm/trino-operator/templates/_helpers.tpl: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.appname
    operator.chart
    operator.fullname
    operator.image
    operator.labels
    operator.name
    operator.selectorLabels
    operator.serviceAccountName
    operator.testLabels
  deploy/helm/trino-operator/templates/_maintenance.tpl: defined templates and the calls to them must be prefixed with 'trino-operator.'
    maintenance.envVars
  deploy/helm/trino-operator/templates/_telemetry.tpl: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.appname
    telemetry.envVars
  deploy/helm/trino-operator/templates/clusterrole-operator.yaml: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.fullname
    operator.labels
    operator.name
  deploy/helm/trino-operator/templates/clusterrole-product.yaml: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.labels
    operator.name
  deploy/helm/trino-operator/templates/deployment.yaml: defined templates and the calls to them must be prefixed with 'trino-operator.'
    maintenance.envVars
    operator.appname
    operator.fullname
    operator.image
    operator.labels
    operator.selectorLabels
    operator.serviceAccountName
    telemetry.envVars
  deploy/helm/trino-operator/templates/service.yaml: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.fullname
    operator.labels
    operator.selectorLabels
  deploy/helm/trino-operator/templates/serviceaccount.yaml: defined templates and the calls to them must be prefixed with 'trino-operator.'
    operator.fullname
    operator.labels
    operator.serviceAccountName

This was a checkout before the rollout of #645
It succeeds on main now.

stackabletech/issues#882

[Techassi]

LGTM, just a two more variable rename suggestion.