Changes to Search global news articles

for the query request parameter timespan, default value was changed from 3days to 24h

added the non-success response with the status 500

added the optional property meta/stale_since to the response with the 200 status

added the optional property meta/data_age_days to the response with the 200 status

added the optional property meta/notes to the response with the 200 status

added the optional property meta/period to the response with the 200 status

added the optional property data/articles to the response with the 200 status

added the optional property data/count to the response with the 200 status

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

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

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

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

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

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

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

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

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

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

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

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