Feature Request: Verbose Mode for functions retrieving lots of records

[ronrest]

For some queries that retrieve lots of records (and take a long time to run), the user experience would be improved if we allow the user to receive some feedback on the progress made so far. Eg, by adding a verbose argument.

If the data is being retrieved in batches, then it could print out the number of items it has retrieved so far.

My current thought, is to have the progress show up as a single line, which gets cleared and overwritten with every batch of data it receives. Something along the lines of

>>> client.get_studies(verbose=True)
received 150 items

And if the user specifies an upper limit to the number of items to retrieve, using the max_items argument outlined in gihub issue#130, then it could display something like this:

>>> client.get_studies(max_items=200, verbose=True)
received 150 items (out of a max of 200)

I am happy to implement this, but I want to get peoples feedback, and suggestions.