Creates (UCAN) delegation that gives specified agent an access to
specified ability (passed as access.can field) on the this space.
Optionally, you can specify access.expiration field to set the
Creates a (UCAN) delegation that gives full access to the space to the
specified account. At the moment we only allow did:mailto principal
to be used as an account.
Represents an owned space, meaning a space for which we have a private key and consequently have full authority over.