Listeners have no way to ignore a previous old value

A listener can register a filter and converter to allow for filtering an event completely or converting the value to a new value. However, an event can contain both an old and new value. The converter can allow a user to convert the new value to whatever they would like. However the old value will still be present in the event. This is fine for local events, but a for clustered event this old value is shipped to the remote node.

We should change the CacheEventFilterConverter to optionally not return the old value which can be used to reduce payload sizes. This is especially beneficial for near cache which doesn't care about either old or new value at all.