NPC refactor (#10122)

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Server/NPC/Systems/NPCPerceptionSystem.RecentlyInjected.cs

@@ -0,0 +1,23 @@
+using Content.Server.NPC.Components;
+
+namespace Content.Server.NPC.Systems;
+
+public sealed partial class NPCPerceptionSystem
+{
+    /// <summary>
+    /// Tracks targets recently injected by medibots.
+    /// </summary>
+    /// <param name="frameTime"></param>
+    private void UpdateRecentlyInjected(float frameTime)
+    {
+        foreach (var entity in EntityQuery<NPCRecentlyInjectedComponent>())
+        {
+            entity.Accumulator += frameTime;
+            if (entity.Accumulator < entity.RemoveTime.TotalSeconds)
+                continue;
+            entity.Accumulator = 0;
+
+            RemComp<NPCRecentlyInjectedComponent>(entity.Owner);
+        }
+    }
+}