Investigate what more statistics and debug functionality can be added to get insight into dhandle usage (specifically interact with the checkpoint).

The ticket will also add these statistics to the code.
Initially, we will like to add a lot of statistics that we can pull in our testing to get feedback on how much we have improved. Some of those statistics will not make sense to be added to develop. Similarly with debugging functionality that might not make it to develop.

We will push these changes to a holding branch for the duration of the project and eventually discard the branch after the project. We will evaluate what stats/debugging would make sense in the long term, and will pull in those bits into develop.

We will close this ticket once we have figured out an initial set of statistics.