Cancelled slashes by era and validator with maximum slash fraction to be cancelled.
When slashes are cancelled by governance, this stores the era and the validators
whose slashes should be cancelled, along with the maximum slash fraction that should
be cancelled for each validator.
Cancelled slashes by era and validator with maximum slash fraction to be cancelled.
When slashes are cancelled by governance, this stores the era and the validators whose slashes should be cancelled, along with the maximum slash fraction that should be cancelled for each validator.