Expose `inspect-secrets` in the clojure api

[jjttjj]

Currently secrets inspect can be done via the command line, but it also can be nice to do this from the repl. Copying the code here, we could just do

(defn inspect-secrets []
  (secrets/with-secrets
    (pprint/pprint
      (walk/postwalk
        (fn [x]
          (try
            ;; Replace any "leaves" (the bottom levels of the hierarchy, i.e.
            ;; the actual secrets)
            (let [is-leaf? (and (map-entry? x) (not (map? (val x))))]
              (if is-leaf?
                [(key x) "***"]
                x))
            (catch Throwable ex)))
        (secrets/secrets)))))

Any reason not to add this (and make the cli function use it)?