Adds a new member for an XID - either an addressable member such as a
wallet, or an installation acting on behalf of an address.
A key-pair that has been associated with one role MUST not be permitted to be
associated with a different role.
Changes the recovery identifier for an XID. The new recovery identifier must be
a current member of the XID; it keeps the role if it is later revoked as a
member. In addition to being able to add members, the recovery identifier can
also revoke members.
The first entry of any XID log. The XID must be deterministically derivable
from the address and nonce.
The recovery address defaults to the initial associated_address unless
there is a subsequent ChangeRecoveryAddress in the log.