Create a basic operator

[siegfriedweber]

The operator should be able to deploy a working OpenSearch instance where all necessary configurations can be done via overrides.

A smoke test should be provided.

The operator may use the official OpenSearch image as long as the image from Stackable is not yet created.

Part of #1

Tasks

• Fix the deployment via Helm #3
• Decision: Mapping of OpenSearch node types to roles #8
• Basic operator #10
• feat: Add OpenSearch operator ci#136
• feat: Add OpenSearch to the README file operator-templating#541
• feat: Add the product "opensearch" stackable-cockpit#400
• chore: Release stackablectl 1.1.0 stackable-cockpit#401
• test: Disable memory mapping #11
• feat: Add the opensearch-operator to the dev release release#37
• Add opensearch-operator documentation#758
• Hide OpenSearch on released versions documentation#759
• Add OpenSearch documentation-ui#135
• Add opensearch-operator crddocs#51
• Document the OpenSearch operator #14
• Add OpenSearch to Supported product versions
• Add the product to the private organization README
• feat: Make OPENSEARCH_HOME and OPENSEARCH_PATH_CONF overridable #18
• Add the opensearch-operator to SecObserve
• docs: Update examples #27
• Remove the demo configuration of the OpenSearch Security plugin docker-images#1228
• Fix technical debts #20
• docs: Extend the CRD documentation #29
• test: Disable the disk allocation decider #30
• test: Add unit tests #32
• feat: Improve name types #35
• doc: Add external link icons #36
• chore: Upgrade dependencies #37