Add support for collections in OpenApiResponse

[cnizzardini]

Adds support for "collections" in custom response schema, example:

#[OpenApiResponse(schemaType: 'collection', schema: TrimItem::class)]
public function index()

This will output the following OpenAPI YAML:

responses:
  '200':
    description: ''
    content:
      application/json:
        schema:
          properties:
            data:
              items:
                type: object
                properties:
                  your_custom_schema_properties_here:
                    type: string
              type: array
          allOf:
            - $ref: '#/x-swagger-bake/components/schemas/Generic-Collection'