[BE] [c10d][send] Improve error message on dist.send() with destination rank as itself (#89004)
This improves error msg on dist.send() and add corresponding test in test_c10d_common.py(https://github.com/pytorch/pytorch/blob/master/test/distributed/test_c10d_common.py).
Context in issue#83912: https://github.com/pytorch/pytorch/issues/83912
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89004
Approved by: https://github.com/H-Huang
