Port medibot + bot spawners from nyano (#9854)

* Port medibot + bot spawners from nyano

* Make the injection thresholds constants

* Remove warning

* Check against const in system too

* resolving systems just isn't worth it

* only resolve entity manager once

* Reduceother resolves too

* fix post-merge

* woops

Content.Server/AI/Tracking/RecentlyInjectedSystem.cs

@@ -0,0 +1,25 @@
+namespace Content.Server.AI.Tracking
+{
+    public sealed class RecentlyInjectedSystem : EntitySystem
+    {
+
+        Queue<EntityUid> RemQueue = new();
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+            foreach (var toRemove in RemQueue)
+            {
+                RemComp<RecentlyInjectedComponent>(toRemove);
+            }
+            RemQueue.Clear();
+            foreach (var entity in EntityQuery<RecentlyInjectedComponent>())
+            {
+                entity.Accumulator += frameTime;
+                if (entity.Accumulator < entity.RemoveTime.TotalSeconds)
+                    continue;
+                entity.Accumulator = 0;
+                RemQueue.Enqueue(entity.Owner);
+            }
+        }
+    }
+}