feat: Add structured output of products and their versions in bake.py

[lfrancke]

As it says on the tin.
This prints a JSON structure of the current products and their versions.

The output will look like this:

venv-test) on ☁  lars.francke@stackable.tech
❯ bake --show-products
{
  "airflow": [
    "2.9.2",
    "2.9.3",
    "2.10.2"
  ],
  "druid": [
    "26.0.0",
    "30.0.0"
  ],
  "hadoop": [
    "3.3.4",
    "3.3.6",
    "3.4.0"
  ],
  "hbase": [
    "2.4.18",
    "2.6.0"
  ],
  "hello-world": [
    "0.0.1-SNAPSHOT"
  ],
  "hive": [
    "4.0.0",
    "3.1.3"
  ],
  "java-base": [
    "8",
    "11",
    "17",
    "21",
    "22"
  ],
  "java-devel": [
    "8",
    "11",
    "17",
    "21",
    "22"
  ],
  "kafka": [
    "3.7.1",
    "3.8.0"
  ],
  "krb5": [
    "1.21.1"
  ],
  "vector": [
    "0.41.1"
  ],
  "nifi": [
    "1.27.0",
    "2.0.0"
  ],
  "omid": [
    "1.1.2"
  ],
  "opa": [
    "0.66.0",
    "0.67.1"
  ],
  "spark-k8s": [
    "3.5.1",
    "3.5.2"
  ],
  "stackable-base": [
    "1.0.0"
  ],
  "superset": [
    "4.0.2"
  ],
  "trino-cli": [
    "455"
  ],
  "trino": [
    "451",
    "455"
  ],
  "kafka-testing-tools": [
    "1.0.0"
  ],
  "kcat": [
    "1.7.0"
  ],
  "testing-tools": [
    "0.2.0"
  ],
  "zookeeper": [
    "3.9.2"
  ],
  "tools": [
    "1.0.0"
  ],
  "statsd_exporter": [
    "0.27.1"
  ]
}

[lfrancke]

Thanks for assigning @siegfriedweber - this PR is not urgent.

[razvan]

I think it's worth a changelog entry. Otherwise nice.

[lfrancke]

This is in preparation for a Nushell completion script so I can just do --product hb<tab> to get --product hbase and then another <tab> to get the versions.

I can add a changelog entry.

[razvan]

lgtm