Propagate "targets_at" changes in program to child projects
Propagate "targets_at" changes in program to child projects

It's required in order for checks to run at the period or indicator level.
This impacts the Project Editor (frontend) as well as exports (TODO).

#4755 Invalid periods from targetsAt = period stay invalid in targetsAt = indicator
akvo/akvo-rsr,akvo/akvo-rsr,akvo/akvo-rsr,akvo/akvo-rsr