[package] implement get_resource_reader API (#51674)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51674

See
https://docs.python.org/3/library/importlib.html#importlib.abc.ResourceReader

Test Plan: Imported from OSS

Reviewed By: zdevito

Differential Revision: D26237034

Pulled By: suo

fbshipit-source-id: 4c19f6172d16b710737528d3de48372873b9368d

torch/csrc/jit/python/init.cpp

@@ -991,6 +991,11 @@ void initJITBindings(PyObject* module) {
             std::tie(data, size) = self.getRecord(key);
             return py::bytes(reinterpret_cast<const char*>(data.get()), size);
           })
+      .def(
+          "has_record",
+          [](PyTorchStreamReader& self, const std::string& key) {
+            return self.hasRecord(key);
+          })
       .def(
           "get_storage_from_record",
           [](PyTorchStreamReader& self,