Deid logging update

[shubham-s-agarwal]

This minor update is to document chunking (better) and add logging for it as well

[mart-r]

Let's use lazy evaluation in logging unless there's an explicit reason not to.

[mart-r]

Looks good.

Maybe the only left over comment:

Is this all the logging DeID needs? Perhaps there's need for more logging somewhere? If so, would be great to address it all at once. If this is all we need, then great!

[shubham-s-agarwal]

I feel we've covered all of it.
Tom please let me know in case you feel we could add it anywhere else.

[tomolopolis]

fine without further debug statements. Adding debug elsewhere you see fit is up to you, but the Trainer callback also has the same purpose

[tomolopolis]

lgtm