Konnect CRDs: use `additionalProperties` defined on types

[pmalek]

Problem statement

#3592 introduces CRD generation based on Konnect OAS.

This issue tracks the effort of support for parsing additionalProperties on types, e.g.:

    LabelsUpdate:
      description: |
        Labels store metadata of an entity that can be used for filtering an entity list or for searching across entity types. 

        Labels are intended to store **INTERNAL** metadata.

        Keys must be of length 1-63 characters, and cannot start with "kong", "konnect", "mesh", "kic", or "_".
      type: object
      example:
        env: test
      additionalProperties:
        type: string
        pattern: '^[a-z0-9A-Z]{1}([a-z0-9A-Z-._]*[a-z0-9A-Z]+)?$'
        minLength: 1
        maxLength: 63
        nullable: true
      maxProperties: 50
      nullable: true
      writeOnly: true

and translating them into field kubebuilder tags or CEL validation rules.