Ports timed_action_flags & centralizes do_afters #15778

Job	Run time
Compile Maps	52s
Run Linters	2m 53s
Windows Build	2m 19s
Integration Tests (BASIC_TESTS) / run_integration_tests	3m 24s
Integration Tests (CREATE_AND_DESTROY_TEST) / run_integration_tests	2m 38s
Integration Tests (PLANET_GEN_TEST) / run_integration_tests	4m 55s
Integration Tests (RUIN_PLACEMENT_TEST) / run_integration_tests	4m 34s
Integration Tests (SHIP_PLACEMENT_TEST) / run_integration_tests	10m 7s
	31m 42s

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