Reland "[RPC] Use qualified name str directly in RPC torch script code path" (#35489)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35489
Relanding https://github.com/pytorch/pytorch/pull/34733.
Fix is in https://github.com/pytorch/pytorch/pull/34988
Test Plan:
```
buck test mode/dev-nosan //caffe2/test/distributed/rpc:rpc_fork
```
```
buck test mode/dev-nosan //caffe2/test/distributed/rpc/jit:rpc_fork
buck build mode/dev-nosan //caffe2/test/distributed/rpc/jit:rpc_fork && \
buck-out/gen/caffe2/test/distributed/rpc/jit/rpc_fork\#binary.par \
-r test_return_local_script_class_rref_in_py_and_use_in_script
buck build mode/dev-nosan //caffe2/test/distributed/rpc/jit:rpc_fork && \
buck-out/gen/caffe2/test/distributed/rpc/jit/rpc_fork\#binary.par \
-r test_return_local_script_module_rref_in_py_and_use_in_script
```
Differential Revision: D20661748
fbshipit-source-id: d550daab8d689d0a9aa2450f3bdb7417ab79dae2
