C# 9 Cleanup (#325)

- [X] Removes EventArgs - not needed
- [X] Merges sequential checks
- [X] Removes redundant type declarations

Projects/Server/Mobiles/AggressorInfo.cs

@@ -7,7 +7,7 @@ namespace Server
 {
     public class AggressorInfo
     {
-        private static readonly Queue<AggressorInfo> m_Pool = new Queue<AggressorInfo>();
+        private static readonly Queue<AggressorInfo> m_Pool = new();
         private Mobile m_Attacker, m_Defender;
         private bool m_CanReportMurder;
         private bool m_CriminalAggression;