CRDGenerator: Support for ListType

[baloo42]

Is your enhancement related to a problem? Please describe

In Kubernetes the topology of lists/arrays can be described further:

https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.31/#jsonschemaprops-v1-apiextensions-k8s-io

List restrictions are sometimes required to apply CEL validation rules. Those rules can't be used at the moment because we don't offer a way to configure the topology.

Relates to #5881

Describe the solution you'd like

Suggested Annotations:

/**
 * Annotates a list or array to further describe its topology.
 * <p>
 * Emits {@code x-kubernetes-list-type}
 * </p>
 */
@Target({ ElementType.FIELD, ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
public @interface ListType {

  /**
   * @return the list type
   */
  Type value() default Type.ATOMIC;

  /**
   * @return the map keys. Only used if {@link Type} is {@link Type#MAP}.
   */
  String[] mapKeys() default {};

  /**
   * The Kubernetes List Type
   */
  enum Type {
    /**
     * The list is treated as a single entity, like a scalar.
     * Atomic lists will be entirely replaced when updated.
     */
    ATOMIC,

    /**
     * Sets are lists that must not have multiple items with the same value. Each
     * value must be a scalar, an object with x-kubernetes-map-type <code>atomic</code>
     * ({@link MapType.Type#ATOMIC}) or an array with x-kubernetes-list-type
     * <code>atomic</code> ({@link ListType.Type#ATOMIC}).
     */
    SET,

    /**
     * These lists are like maps in that their elements have a non-index key
     * used to identify them. Order is preserved upon merge. The map tag
     * must only be used on a list with elements of type object.
     *
     * @see ListMapKey
     */
    MAP
  }
}

/**
 * Marks a field as key.
 * Only considered if {@link ListType.Type#MAP} is used
 * on the parent container.
 *
 * @see ListType
 */
@Target({ ElementType.FIELD, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface ListMapKey {
}

Describe alternatives you've considered

No response

Additional context

Example:
https://github.com/baloo42/crd-generator-victools/blob/main/test/src/test/java/io/fabric8/crd/generator/victools/approvaltests/listtype/ListTypeSpec.java
https://github.com/baloo42/crd-generator-victools/blob/main/test/src/test/resources/io/fabric8/crd/generator/victools/approvaltests/CRDGeneratorVictoolsApprovalTest.approvalTest.listtypes.samples.fabric8.io.v1.approved.yml

[stale]

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