Refactored pulse running logic, made it easier to follow and debug

Made the pulse runner use thread-safe collections instead of synchronizing on a thread-unsafe list

Server/src/test/kotlin/TestUtils.kt

@@ -55,10 +55,10 @@ object TestUtils {
         }
     }
 
-    fun advanceTicks(amount: Int) {
+    fun advanceTicks(amount: Int, skipPulseUpdates: Boolean = true) {
         SystemLogger.logInfo("Advancing ticks by $amount.")
         for(i in 0 until amount) {
-            GameWorld.majorUpdateWorker.handleTickActions()
+            GameWorld.majorUpdateWorker.handleTickActions(skipPulseUpdates)
         }
     }
 }