TriggerEventSeen spam caused by player viewing feature object just before offworld load

[KJeff01]

Describe the bug
TriggerEventSeen can get spammed a ton in campaign logs. This seemingly stems from the player having vision on feature objects just before offworld mission load occurs.

To Reproduce
Steps to reproduce the behavior:

1. Have any feature on a home-base map within vision range (may or may not require a sensor-like object).
2. See assert spam upon going offworld.
3. Remove said features from the map and no assert spam.

Expected behavior
No spam.

Additional context
gameLoop -> gameStateUpdate() -> processVisibility() -> processVisibilityVision() (spam potential starts here cause scriptsReady will be false for a time until stageThreeInit happens).

Not sure why we care about updating vision as the game is in a loading screen state trying to go offworld.

This problem also isn't entirely confined to this event. In rare cases, I can also see eventDroidIdle also pop up before scripts are ready. The game also automatically builds any structures a truck was working on in saveMissionData(), and thus eventStructureBuilt can fire off during the loading screen as well.