Added caching util function with tests and applied in:
- parser.Block.Transactions(),
- parser.Payload.ChannelHeader(),
- parser.Payload.SignatureHeader(),
- parser.NamespaceReadWriteSet.ReadWriteSet(),
- parser.EndorserTransaction.ReadWriteSets(),
methods, as it was in the typescript sample.
Corrected Println usage and added comments to util functions.
Signed-off-by: Stanislav Jakuschevskij <stas@two-giants.com>
