feat: new CEL function to check existence of a relationship to a type

[adityathebe]

Use case

dyn(config).
  filter(item, catalog.hasRelationToType(item.app_id, "MissionControl::Application")).
  map(item, {
    "access_logs": [{
      "config_id": item.app_id,
      "external_user_id": item.user_id,
      "created_at": item.created_at
    }]
  }).toJSON()

[moshloop]

Couldn't this just be len(catalog.traverse(item.app_id, "MissionControl::Application")) > 0 .

[adityathebe]

@moshloop ya it's essentially just that.