This was originally attempted by policy CMP0118, but its
implementation did not cover all intended use cases. We fixed its
documentation in commit 1dabbbb5e0 (CMP0118: Revise documentation to
describe actual behavior, 2024-03-20).
Add new policy CMP0163 to cover the remaining use cases. In particular,
make the `GENERATED` property visible to `get_property` calls in other
directories. In order to capture the original intention of CMP0118,
define CMP0163's NEW behavior to also imply CMP0118's NEW behavior.
Fixes: #25437Fixes: #25058
