Provide source file info in find functions

From: https://ask.clojure.org/index.php/8826/would-nice-tools-namespace-find-functions-return-file-info

Currently calling tools.namespace.find/find-ns-decls returns a seq of ns-decl for a given dir or collection of paths but there is no way to know where did they came from (can also be coming from paths inside jar files).

Looks pretty straight forward to add file info as meta of the ns-decl form. Something like https://github.com/jpmonettas/tools.namespace/commit/1431215324ba7f76f78342742ce3716ec8c5abb8