Type Alias ErasValidatorPrefs

ErasValidatorPrefs: StorageDescriptor<
    [number, SS58String],
    { blocked: boolean; commission: number },
    false,
    never,
>

Exposure of validator at era with the preferences of validators.

This is keyed first by the era index to allow bulk deletion and then the stash account.

Is it removed after [Config::HistoryDepth] eras.