Summary: This allows us to start alerting on cache failures, based on scuba data
Test Plan:
Added new tests explicitly for the Remote Cache API.
Note that we have existing tests for memcache, but not for manifold AFAICT.
There are two potential wrinkles. One we're adding a new field (and everything uses ScubaData AFAICT, so this should just work).
The other one is the implicit api contract that if the sample is None, then it will be ignored (and not crash). I believe the second one is implemented correctly (and tested). The first one is a little more nebulous, but I think won't cause any breakages.
Also manually ran a compile and made sure it didn't break - P1851504490 as well as forcing it to break and checking we didn't screw up the exception handling - P1851504243
Rollback Plan:
Differential Revision: D77054339
Pull Request resolved: https://github.com/pytorch/pytorch/pull/156874
Approved by: https://github.com/oulgen, https://github.com/masnesral
