Instrument entire namespaces for sampling fn args and return values.

The main entry point is flow-storm.fn-sampler.core/sample

When instrumented namespaces code runs, the sampler will collect fns
into a map {fully-qualified-fn-symbol-1 {:args-types #{...}
                                         :return-types #{...}
                                         :call-examples #{...}
                                         :var-meta {...}}
            fully-qualified-fn-symbol-2 {...}
            ...}

end save it into a edn file then wrapped into a jar.

:args-type is a set of vectors with sampled types descriptions.

:return-types is a set of sampled types descriptions.

:call-examples is a set of {:args [sv] :ret sv} where sv is the value serialization of the sampled value.
               See `serialize-val` to see how values get serialized.

:var-meta is meta as returned by Clojure (meta (var fully-qualified-fn-symbol))