Changes to List conversations

added the new optional query request parameter recipient

added the new optional query request parameter spam

added the optional property conversations/items/lastMessagePreview to the response with the 200 status

added the optional property conversations/items/recipientAddress to the response with the 200 status

added the optional property conversations/items/spam to the response with the 200 status

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

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

added the optional property issues to the response with the 503 status

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

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

added the optional property retryable to the response with the 503 status

added the non-success response with the status 503

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

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

the response property success became optional for the status 400

the response property success became optional for the status 401

endpoint added