### 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.
### Summary
Adds a generic entity persistence. This can be used to create new entity types that have a `Serial`.
Here is an example:
```cs
public class BOBEntries : GenericEntitySerialization<IBOBEntry>
{
public static void Configure()
{
Configure("BOBEntries");
}
}
```
The annotation tells the system what folder to serialize the entries to. The class/interface (`IBOBEntry`) is the root type that implements `ISerializable`.
