This type can only be created in the transaction that
generates a module, by consuming its one-time witness, so it
can be used to identify the address that published the package
a type originated from.
Issued as a result of a successful upgrade, containing the
information to be used to update the UpgradeCap. This is a “Hot
Potato” to ensure that it is used to update its UpgradeCap before
the end of the transaction that performed the upgrade.
Permission to perform a particular upgrade (for a fixed version of
the package, bytecode to upgrade with and transitive dependencies to
depend against).