fix: Cleans up entity persistence. Generalizes Mobiles/Items/Guilds (#1528)

### Summary
- [X] Fixed a bug where entity persistence was serialized out of order, causing world corruption.
- [X] Fixed LastSerialized not being utilized properly and dangling references still becoming an issue.
- [X] Added a new `GenericEntityPersistence<T>` type to encapsulate `ISerializable` serialization.
- [X] Removing the custom logic and moved Items, Mobiles, Guilds, and Accounts  to GenericEntityPersistence.
- [X] Changed serialization to use the singleton pattern to reduce calling methods from stored variables.

Projects/UOContent/Mobiles/AI/BaseAI.cs

@@ -2702,7 +2702,7 @@ public abstract class BaseAI
             }
 
             // Ignore players with activated honor
-            if (m_Mobile.Combatant != m && pm?.GetVirtues()?.HonorActive == true)
+            if (m_Mobile.Combatant != m && VirtueSystem.GetVirtues(pm)?.HonorActive == true)
             {
                 continue;
             }

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -1288,7 +1288,7 @@ namespace Server.Mobiles
                 return false;
             }
 
-            if ((m as PlayerMobile)?.GetVirtues()?.HonorActive == true)
+            if (VirtueSystem.GetVirtues(m as PlayerMobile)?.HonorActive == true)
             {
                 return false;
             }

Projects/UOContent/Mobiles/PlayerMobile.cs

@@ -697,30 +697,32 @@ namespace Server.Mobiles
         }
 
         [CommandProperty(AccessLevel.GameMaster, canModify: true)]
-        public ChampionTitleContext ChampionTitles => this.GetOrCreateChampionTitleContext();
+        public ChampionTitleContext ChampionTitles => ChampionTitleSystem.GetOrCreateChampionTitleContext(this);
 
         [CommandProperty(AccessLevel.GameMaster)]
         public int ShortTermMurders
         {
-            get => this.GetMurderContext(out var context) ? context.ShortTermMurders : 0;
+            get => PlayerMurderSystem.GetMurderContext(this, out var context) ? context.ShortTermMurders : 0;
             set => PlayerMurderSystem.ManuallySetShortTermMurders(this, value);
         }
 
         [CommandProperty(AccessLevel.GameMaster)]
-        public DateTime ShortTermMurderExpiration => this.GetMurderContext(out var context) && context.ShortTermMurders > 0
-            ? Core.Now + (context.ShortTermElapse - GameTime)
-            : DateTime.MinValue;
+        public DateTime ShortTermMurderExpiration
+            => PlayerMurderSystem.GetMurderContext(this, out var context) && context.ShortTermMurders > 0
+                ? Core.Now + (context.ShortTermElapse - GameTime)
+                : DateTime.MinValue;
 
         [CommandProperty(AccessLevel.GameMaster)]
-        public DateTime LongTermMurderExpiration => Kills > 0 && this.GetMurderContext(out var context)
-            ? Core.Now + (context.LongTermElapse - GameTime)
-            : DateTime.MinValue;
+        public DateTime LongTermMurderExpiration
+            => Kills > 0 && PlayerMurderSystem.GetMurderContext(this, out var context)
+                ? Core.Now + (context.LongTermElapse - GameTime)
+                : DateTime.MinValue;
 
         [CommandProperty(AccessLevel.GameMaster)]
         public int KnownRecipes => m_AcquiredRecipes?.Count ?? 0;
 
         [CommandProperty(AccessLevel.Counselor, canModify: true)]
-        public VirtueContext Virtues => this.GetOrCreateVirtues();
+        public VirtueContext Virtues => VirtueSystem.GetOrCreateVirtues(this);
 
         public HonorContext ReceivedHonorContext { get; set; }
 
@@ -1255,7 +1257,7 @@ namespace Server.Mobiles
 
             if (from is PlayerMobile mobile)
             {
-                mobile.CheckAtrophies();
+                VirtueSystem.CheckAtrophies(mobile);
                 mobile.ClaimAutoStabledPets();
             }
         }
@@ -3426,7 +3428,7 @@ namespace Server.Mobiles
             // https://uo.com/wiki/ultima-online-wiki/player/skill-titles-order/
             if (DisplayChampionTitle)
             {
-                var titleLabel = this.GetChampionTitleLabel();
+                var titleLabel = ChampionTitleSystem.GetChampionTitleLabel(this);
                 if (titleLabel > 0)
                 {
                     list.Add(titleLabel);

Projects/UOContent/Mobiles/Townfolk/BaseEscortable.cs

@@ -643,7 +643,7 @@ public partial class BaseEscortable : BaseCreature
 
             if (escorter is PlayerMobile pm)
             {
-                var virtues = pm.GetOrCreateVirtues();
+                var virtues = VirtueSystem.GetOrCreateVirtues(pm);
                 if (virtues.CompassionGains > 0 && Core.Now > virtues.NextCompassionDay)
                 {
                     virtues.NextCompassionDay = DateTime.MinValue;