Fixes some overlay screwery on death and revival (#15192)

* Toggles fullscreens off/on on death/revival instead of deleting them

Fixes a lot of issues regarding fullscreens (vulpkanin NV/welding shield
overlay vanishing, crit overlay not persisting on defib)

* Restores blind effect when defibrillated back to life

Fixes issue where the blind overlay wouldn't appear
when defibrillated, even though the patient is
unconscious/blind

code/game/objects/items/weapons/defib.dm

@@ -428,8 +428,8 @@
 						H.adjustBruteLoss(tobehealed)
 						user.visible_message("<span class='boldnotice'>[defib] pings: Resuscitation successful.</span>")
 						playsound(get_turf(src), 'sound/machines/defib_success.ogg', 50, 0)
-						H.update_revive(FALSE)
-						H.KnockOut(FALSE)
+						H.update_revive()
+						H.KnockOut()
 						H.Paralyse(5)
 						H.emote("gasp")
 						if(tplus > tloss)