Expose whether sharding has happened, and how many times

[micahr]

Mostly for metrics / reporting, but useful context for applications.

[DonutEspresso]

Seems like we could probably also expose the names of the conductors that were sharded, like a history of sorts.

Any preference as to how these metrics are exposed? Via a metrics event periodically?

[micahr]

A sorted array with the previous conductors would be great.