fix: Fixes various memory leaks and spells (#1786)

### Summary
- Fixes various memory leaks related to spells
- Fixes Spell Plague
- Added ability to determine if `sdi` should take effect for Spell Damage.
- Fixes animal form timer ticking non-stop while logged out.

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -2395,13 +2395,17 @@ namespace Server.Mobiles
                 AnimateDeadSpell.Unregister(m_SummonMaster, this);
             }
 
+            if (Summoned && SummonMaster != null)
+            {
+                SummonFamiliarSpell.Unregister(SummonMaster, this);
+            }
+
             if (MLQuestSystem.Enabled)
             {
                 MLQuestSystem.HandleDeletion(this);
             }
 
             UnsummonTimer.StopTimer(this);
-
             StaminaSystem.RemoveEntry(this as IHasSteps);
 
             base.OnAfterDelete();

Projects/UOContent/Mobiles/PlayerMobile.cs

@@ -1216,7 +1216,7 @@ namespace Server.Mobiles
             }
         }
 
-        public static void OnLogin(Mobile from)
+        public static void OnLogin(PlayerMobile from)
         {
             if (AccountHandler.LockdownLevel > AccessLevel.Player)
             {
@@ -1253,11 +1253,9 @@ namespace Server.Mobiles
                 return;
             }
 
-            if (from is PlayerMobile mobile)
-            {
-                VirtueSystem.CheckAtrophies(mobile);
-                mobile.ClaimAutoStabledPets();
-            }
+            VirtueSystem.CheckAtrophies(from);
+            from.ClaimAutoStabledPets();
+            AnimalForm.GetContext(from)?.Timer.Start();
         }
 
         private class ServerLockdownNoticeGump : StaticNoticeGump<ServerLockdownNoticeGump>
@@ -2561,6 +2559,7 @@ namespace Server.Mobiles
             PolymorphSpell.StopTimer(this);
             IncognitoSpell.StopTimer(this);
             DisguisePersistence.RemoveTimer(this);
+            AnimalForm.RemoveContext(this, true);
 
             EndAction<PolymorphSpell>();
             EndAction<IncognitoSpell>();