fix: Add additionalProperties annotations to match benchmark schema

[mahdanoura]

addresses point 2 of #28

This PR adds support for controlling additionalProperties in the generated JSON Schema by leveraging LinkML's annotation system. Since LinkML does not directly support the JSON Schema additionalProperties vocabulary, we implemented this using LinkML annotations with the following structure:

annotations:
  jsonschema_config:
    tag: jsonschema_config
    value:
      additionalProperties: true

The annotations have been added to:

• Core interaction affordance classes (PropertyAffordance, ActionAffordance, EventAffordance)
• Hypermedia controls (Form, Link)
• Data schema classes (DataSchema and all its subclasses)
• Security scheme classes (SecurityScheme and all its implementations)