Refactor all legacy TriggeredEffects that express both a condition and a consequence in one (e.g. SlideObjectWhenDeadBodyEnters.cs) into trigger->consequence pattern

[sapphon]

This work also includes replacing any uses of these scripts in Level 1.unity with the new versions.

• [x] Explode.cs
• [x] SetRespawnTrigger,cs
• [x] PressurePlate.cs
• [x] Player Killer.cs (scene work only, scripts already exist)
• [ ] SlideObjectWhenDeadBodyEnters.cs
• [x] ExplodeAndDestroy
• [x] Grabber
• [x] ChangeTextureOnEnter
• [x] ActivateRigidbodyOnTrigger

[sapphon]

Ended up just deleting Grabber as it was unused in prod