Provide cache entry meta data without necessity to set expiration

The creation and lastUsed times are only set if the related expiration, based on lifespan for creation time and maxIdle for lastUsedTime, is configured or used for the specific entry.

For some reasons it might be interesting to have that times available for application purpose.

To be able to suppress the timestamps because of performance and space issues as the metadata will need a few bytes in memory and storage
it seems reasonable if a configuration is needed to enable this