Make targets report an error on faulty INTERFACE on IMPORTED targets.

It is considered an error if the INTERFACE_INCLUDE_DIRECTORIES contains
a directory which does not exist, which indicates a programmer error
by the upstream, or a packaging error.

One of the RunCMake.CompatibleInterface tests also needs to be updated
due to this change. Non-existant includes were used in the test, but
are not needed.
Merge topic 'error-on-exported-missing-include-dir' into next

13278bc Make targets report an error on faulty INTERFACE on IMPORTED targets.