Issues with read-write asset benchmark/chaincode

[davidkel]

When creating assets it's possible that it doesn't create all the assets required. may get worse the higher the number of assets.
This might be the reason for chaincode reporting "unexpected end of JSON" when an asset is requested to be read, the larger the number of assets defined the more frequent this error occurs (eg 1,000,000 assets shows this problem but it was also noticeable with asset counts over 200,000.

This read-write asset chaincode and benchmark need the following fixed

• chaincode should detect if an asset doesn't exist and return an error saying so
• the create and delete workloads should output their activity as they go along
• we could use a chaincode query to test that all the assets exist
• we should output the asset range for each worker

[davidkel]

Most of these are fixed now, don't think it's worth doing all of them so can consider this closed