[TensorPipe] Pass names of endpoints to context/pipe for easier debugging (#38926)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38926
TensorPipe supports for the user to provide a meaningful name for each context and to specify what it thinks the name of the endpoint it's connecting to is, so that these names can be logged and matched to the otherwise not-very-informative ID of a pipe (given by the PID and some counters) for easier debugging.
ghstack-source-id: 104760688
Test Plan: Ran RPC tests with `TP_VERBOSE_LOGGING=1`.
Differential Revision: D21479799
fbshipit-source-id: 856d2ffac239a3f9b11318a92ba4534133865dc8
