OriginalAccount: StorageDescriptor<
    [Key: FixedSizeBinary<20>],
    SS58String,
    true,
    never,
>

Map a Ethereum address to its original AccountId32.

When deriving a H160 from an AccountId32 we use a hash function. In order to reconstruct the original account we need to store the reverse mapping here. Register your AccountId32 using [Pallet::map_account] in order to use it with this pallet.