Invalid TS models when properties are nullable

[TheMatrix97]

Hi! It seems the openapi connector is not setting the correct TS type when setting true the nullable flag

For example, with the following JSON OpenAPI definition model:

      "TestObject": {
        "type": "object",
        "properties": {
          "name": {
            "type": "string",
            "nullable": true,
             "default": null,
            "description": "Test property",
            "example": null
          },

It creates a model with the following property:

  @property({jsonSchema: {
  type: [
    'string',
    'null',
  ],
  default: null,
  description: 'Specific endpoint for this queue, if not specified, the generic endpoint for this service will be used',
}})
  endpoint?: string = null;

Obviously, as endpoint is set as string, it throws a TS Check error in build time:
error TS2322: Type 'null' is not assignable to type 'string | undefined'.

Why isn't setting the property type correctly, whereas in the type annotation seems to be aware of it?

Thanks!