[codegen] Support generic object property

[brondani]

Changes

• Generate generic C++ map and TS Record for properties with type object and accepting additionalProperties.
  For example the following schema:

Device:
  type: object
  properties:
    name:
      type: string
    attributes:
      type: object
      additionalProperties:
        type: string
  required:
    - name
    - attributes

Results in the following interfaces for C++ and TS respectively:

struct Device {
  string name;
  map<string, string> attributes;
};

export interface Device {
    name: string,
    attributes: Record<string, string>,
}

Checklist

• 🤖 This change is covered by unit tests (if applicable).
• 🤹 Manual testing has been performed (if necessary).
• 🛡️ Security impacts have been considered (if relevant).
• 📖 Documentation updates are complete (if required).
• 🧠 Third-party dependencies and TPIP updated (if required).