[Feature request]: Expose Policy Key when Exceptions Thrown

[matthawley]

Is your feature request related to a specific problem? Or an existing feature?

We are looking at the feasibility of getting the policy key an associated exception is thrown from, specifically BrokenCircuitException. Is there a way this can be added as additional information to this (and other) exceptions when they're thrown?

Describe the solution you'd like

The PolicyKey from the associated circuit breaker policy exposed on BrokenCircuitException.

Additional context

This might be useful for any other exceptions that may be thrown from other policies where the policy key is set.

[martincostello]

This sounds like an effective duplicate of #2345, except for our "v7" API.

If that's the case, we're not really investing in new features in the old API at this stage. Instead if you want to use such functionality, you should migrate to use the new resilience pipeline functionality in Polly.Core from v8+.

[matthawley]

Okay, I'll check that out to see if it helps solve some issues.