Changes to Start a conversation with the agent

added the optional property feature to the response with the 400 status

added the optional property feature to the response with the 401 status

added the optional property feature to the response with the 402 status

added the optional property feature to the response with the 403 status

added the optional property feature to the response with the 404 status

added the optional property feature to the response with the 409 status

added the optional property feature to the response with the 422 status

added the optional property feature to the response with the 429 status

added the optional property required_plan to the response with the 400 status

added the optional property required_plan to the response with the 401 status

added the optional property required_plan to the response with the 402 status

added the optional property required_plan to the response with the 403 status

added the optional property required_plan to the response with the 404 status

added the optional property required_plan to the response with the 409 status

added the optional property required_plan to the response with the 422 status

added the optional property required_plan to the response with the 429 status

added the optional property upgrade_url to the response with the 400 status

added the optional property upgrade_url to the response with the 401 status

added the optional property upgrade_url to the response with the 402 status

added the optional property upgrade_url to the response with the 403 status

added the optional property upgrade_url to the response with the 404 status

added the optional property upgrade_url to the response with the 409 status

added the optional property upgrade_url to the response with the 422 status

added the optional property upgrade_url to the response with the 429 status