Generate operator helm chart

[slamdev]

AIM of this PR is to migrate altinity-clickhouse-operator chart to the official repo.

PR contains a lot of auto-generated files, so it makes sense to review commits individually.

Things yet to cover:

• run ./dev/generate_helm_chart.sh after the script that generates deploy/operator/clickhouse-operator-install-bundle.yaml

Sample of the release pipeline: https://github.com/slamdev/clickhouse-operator/actions/runs/3455712508/jobs/5767926291

Chart archive is attached to a release: https://github.com/slamdev/clickhouse-operator/releases/tag/release-0.20.0

Autogenerated index.yaml: https://github.com/slamdev/clickhouse-operator/blob/gh-pages/index.yaml

Chart is available via github pages:

helm show chart altinity-clickhouse-operator --repo=https://slamdev.github.io/clickhouse-operator

apiVersion: v2
appVersion: 0.20.0
description: Helm chart to deploy [altinity-clickhouse-operator](https://github.com/Altinity/clickhouse-operator).  The
  ClickHouse Operator creates, configures and manages ClickHouse clusters running
  on Kubernetes.
home: https://github.com/Altinity/clickhouse-operator
icon: https://altinity.com/wp-content/uploads/2022/05/logo_horizontal_blue_white.svg
maintainers:
- email: [email protected]
  name: altinity
name: altinity-clickhouse-operator
type: application
version: 0.20.0

Prerequisite: create gh-pages branch and make sure it's empty.

Actions after the first chart release:

• register repo and verify ownership
• replace README content with new chart location
• update operator docs with the chart installation process

closes #1024 #941 #837 #620
partially solves #558

[Slach]

LGTM
but small cosmetic comments

and main concern
if we generate grafana dashboards
could we add optional dependency to Chart.yaml for this use case

[Slach]

could we change it to go-template?