Conformance failure: Vote delegations removed if a DRep is unregistered and reregistered within the same tx

`--match="Delegate vote to a DRep that is unregistered and reregistered in the same transaction`

Start by running the conformance case matched by `Delegate vote to a DRep that is unregistered and reregistered in the same transaction`. Trace the expected delegation behavior across the unregister and reregister steps; the work is done when this matching conformance test passes without removing the vote delegation.

Written by the indexing model from the issue text.