Changes to List GitHub data sources

added the non-success response with the status 502

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

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

added the optional property error/code to the response with the 500 status

added the optional property error/details to the response with the 400 status

added the optional property error/details to the response with the 401 status

added the optional property error/details to the response with the 500 status

added the optional property error/request_id to the response with the 400 status

added the optional property error/request_id to the response with the 401 status

added the optional property error/request_id to the response with the 500 status

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

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

added the optional property error/retryable to the response with the 500 status

added the optional property githubs/items/metadata to the response with the 200 status

endpoint added