add duplicate constant node pass (#2570)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/2570

This diff is the follow up for https://github.com/pytorch/executorch/pull/2424

In the case like
```
    consant_0 (tag_10) ----> op_b (tag_10)
    |-------------> op_a (tag_11)
```

`op_b` and `op_a` are in two delegated payload and `constant_0` have two options:

In this diff, we're making the default behavior as allowing copying, meaning it will become
```
    consant_0 (tag_10)------------------> op_b (tag_10)
    consant_0_copy (tag_11) -------------> op_a (tag_11)
```

The backend can tag the node with `no_copy` to allert users in cases like constants are too large or etc. In this case, a better approach can be
```
    consant_0 (tag_10) ----> op_b (tag_10)
                                    |-----(output consant_0) --------> op_a (tag_11)
```

Reviewed By: angelayi

Differential Revision: D55113232

fbshipit-source-id: 49559a8cc8225b866a399b4db04ef59fc6860cc1