Provide a context manager for running distributed code on a given process first

## 🚀 Feature

```python
import ignite.distibuted as idist

with idist.rank_process_first(rank=1):
    data_setup_code(...)
```
where behind we would be doing something like:
```python
    if idist.get_local_rank() != rank:
        idist.barrier()

    data_setup_code(...)

    if idist.get_local_rank() == rank:
        idist.barrier()
```

