Problem

The Crypto.KeyList, SignatureAlgorithm and HashAlgorithm types do not implement the Storable interface and therefore can't be used as fields inside a resource.

Steps to Reproduce

You can observe the error in this CI run for the keylist branch on the token-cold-storage repository.

execution error code 1101: [Error Code: 1101] cadence runtime error Execution failed:
    error: mismatched types
      --> 56626291fa218bc24cab8d838165ee0887da3b07552d9380e54809801370db7a:39:17
       |
    39 |     account.save(<-coldVault, to: /storage/flowTokenColdStorage)
       |                  ^^^^^^^^^^^ expected `Storable`, got `ColdStorage.Vault`

An alternate version of the same contract that doesn't use Crypto.KeyList passes the same test cases.

Acceptance Criteria

Crypto.KeyList objects can be stored inside of a resource.

Context

I discovered this while writing an example for a team wishing to implement on-chain signature verification.