refactor: module -> module_ with typedef (#2544)

* WIP: module -> module_ without typedef

* refactor: allow py::module to work again
diff --git a/tests/test_iostream.cpp b/tests/test_iostream.cpp
index e67f88a..e916150 100644
--- a/tests/test_iostream.cpp
+++ b/tests/test_iostream.cpp
@@ -37,7 +37,7 @@
     });
 
     m.def("captured_output", [](std::string msg) {
-        py::scoped_ostream_redirect redir(std::cout, py::module::import("sys").attr("stdout"));
+        py::scoped_ostream_redirect redir(std::cout, py::module_::import("sys").attr("stdout"));
         std::cout << msg << std::flush;
     });
 
@@ -46,7 +46,7 @@
             py::arg("msg"), py::arg("flush")=true);
 
     m.def("captured_err", [](std::string msg) {
-        py::scoped_ostream_redirect redir(std::cerr, py::module::import("sys").attr("stderr"));
+        py::scoped_ostream_redirect redir(std::cerr, py::module_::import("sys").attr("stderr"));
         std::cerr << msg << std::flush;
     });
 
@@ -65,8 +65,8 @@
     });
 
     m.def("captured_dual", [](std::string msg, std::string emsg) {
-        py::scoped_ostream_redirect redirout(std::cout, py::module::import("sys").attr("stdout"));
-        py::scoped_ostream_redirect redirerr(std::cerr, py::module::import("sys").attr("stderr"));
+        py::scoped_ostream_redirect redirout(std::cout, py::module_::import("sys").attr("stdout"));
+        py::scoped_ostream_redirect redirerr(std::cerr, py::module_::import("sys").attr("stderr"));
         std::cout << msg << std::flush;
         std::cerr << emsg << std::flush;
     });