Rebind `*print-namespace-maps*`

[vemv]

IME, many people dislike the *print-namespace-maps* default behavior, i.e. print namespaced maps at the repl.

It seems to me that cider-nrepl could change this default?

Right now, we observe options such as:

  nrepl.middleware.print/options     (dict
                                       right-margin 70)

If we change the default, these options look like a nice place to let users opt out.