Changes to Mining reward statistics

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

the response property data/block_count became optional for the status 200

the response property data/endBlock became optional for the status 200

the response property data/startBlock became optional for the status 200

the response property data/totalFee became optional for the status 200

the response property data/totalReward became optional for the status 200

the response property data/totalTx became optional for the status 200

response property data/block_count list-of-types was widened by adding types null and number to media type application/json of response 200

response property data/endBlock list-of-types was widened by adding types null and number to media type application/json of response 200

response property data/startBlock list-of-types was widened by adding types null and number to media type application/json of response 200

response property data/totalFee list-of-types was widened by adding types null to media type application/json of response 200

response property data/totalReward list-of-types was widened by adding types null to media type application/json of response 200

response property data/totalTx list-of-types was widened by adding types null to media type application/json of response 200

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