Change minibomb to be explosion resistant and start timer on damage (#32429)

* Make minibomb explosion resistant and trigger timer on damage

* Tune damage behaviour and threshold for minibomb

Content.Server/Destructible/Thresholds/Behaviors/TimerStartBehavior.cs

@@ -0,0 +1,10 @@
+namespace Content.Server.Destructible.Thresholds.Behaviors;
+
+[DataDefinition]
+public sealed partial class TimerStartBehavior : IThresholdBehavior
+{
+    public void Execute(EntityUid owner, DestructibleSystem system, EntityUid? cause = null)
+    {
+        system.TriggerSystem.StartTimer(owner, cause);
+    }
+}