Added a SerializableScriptableObject to store asset GUID.

This replaces the previous serialization code. We can use the cached asset GUID to serialize assets to disk as well as load them through the Addressables system.

UOP1_Project/Assets/ScriptableObjects/SaveSystem/SaveSystem.asset

   m_EditorClassIdentifier: 
   locationDatabase: {fileID: 11400000, guid: 9abcccc3f16b8c54e984de463d147899, type: 2}
   _loadLocation: {fileID: 11400000, guid: 00e3063edc5902e40832ea618644c597, type: 2}
+  _onSceneReady: {fileID: 11400000, guid: b729e40fc41dd8b4ea7aaf5c857f7186, type: 2}
-    _locationId: 47723aeb-1bae-48c7-a760-4d6339e4a68a
+    _locationId: 

UOP1_Project/Assets/Scripts/BaseClasses/DescriptionBaseSO.cs

 /// <summary>
 /// Base class for ScriptableObjects that need a public description field.
 /// </summary>
-public class DescriptionBaseSO : ScriptableObject
+public class DescriptionBaseSO : SerializableScriptableObject
 {
 	[TextArea] public string description;
 }

UOP1_Project/Assets/Scripts/SaveSystem/SaveSystem.cs

 
 public class SaveSystem : ScriptableObject
 {
-	public LocationDatabase locationDatabase;
 	[SerializeField] private LoadEventChannelSO _loadLocation = default;
 
 	public string saveFilename = "save.chop";
 		LocationSO locationSo = locationsToLoad[0] as LocationSO;
 		if (locationSo)
 		{
-			saveData._locationId = locationSo.DescId.uuid;
+			saveData._locationId = locationSo.SerializableGuid;
 		}
 	}
 

UOP1_Project/Assets/Scripts/SceneManagement/ScriptableObjects/LocationSO.cs

 using UnityEngine;
 using UnityEngine.Localization;
+
-public class LocationSO : GameSceneSO, IDesc
+public class LocationSO : GameSceneSO
-
-	[Header("Serialization")]
-	[SerializeField] Uuid uuid;
-	public Uuid DescId => uuid;
 }

UOP1_Project/Assets/Scripts/SaveSystem/SerializableScriptableObject.cs

+using UnityEngine;
+
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+public class SerializableScriptableObject : ScriptableObject
+{
+	private string _serializableGuid;
+	public string SerializableGuid => _serializableGuid;
+
+	void OnValidate()
+	{
+#if UNITY_EDITOR
+		var path = AssetDatabase.GetAssetPath(this);
+		_serializableGuid = AssetDatabase.AssetPathToGUID(path);
+#endif
+	}
+}

UOP1_Project/Assets/Scripts/SaveSystem/SerializableScriptableObject.cs.meta

+fileFormatVersion: 2
+guid: cfba650367f74698998618a4a140d696
+timeCreated: 1613591825

UOP1_Project/Assets/ScriptableObjects/SceneData/Locations/LocationDatabase.asset

-%YAML 1.1
-%TAG !u! tag:unity3d.com,2011:
---- !u!114 &11400000
-MonoBehaviour:
-  m_ObjectHideFlags: 0
-  m_CorrespondingSourceObject: {fileID: 0}
-  m_PrefabInstance: {fileID: 0}
-  m_PrefabAsset: {fileID: 0}
-  m_GameObject: {fileID: 0}
-  m_Enabled: 1
-  m_EditorHideFlags: 0
-  m_Script: {fileID: 11500000, guid: a07abb7875a4fc945b9a7cf5212ed565, type: 3}
-  m_Name: LocationDatabase
-  m_EditorClassIdentifier: 
-  _descs:
-  - {fileID: 11400000, guid: 2f386bbc670c05145834a0f9c7d55798, type: 2}
-  - {fileID: 11400000, guid: d102ba8fe3b291249aeb9de4b95c1904, type: 2}
-  - {fileID: 11400000, guid: 3902a4362b3a4fb4ab5ce5dcc07d8427, type: 2}

UOP1_Project/Assets/ScriptableObjects/SceneData/Locations/LocationDatabase.asset.meta

-fileFormatVersion: 2
-guid: 9abcccc3f16b8c54e984de463d147899
-NativeFormatImporter:
-  externalObjects: {}
-  mainObjectFileID: 11400000
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

UOP1_Project/Assets/Scripts/SaveSystem/ISaveable.cs

-using System.Collections.Generic;
-
-public interface ISaveable
-{
-	/// <summary>
-	/// <para>The function which needs to be subscribed to the <see cref="SaveSystem.AddToRegistryCallback"/></para>
-	/// Include it in a place which only gets executed once to avoid data duplication.<br/>
-	/// Like in OnEnable() function of Monobehaviour or ScriptableObject
-	/// </summary>
-	void AddToSaveRegistry(HashSet<ISaveable> registry);
-
-	/// <summary>
-	/// Pure virtual function for saving data to a save file.<br/>
-	/// This will comprise the serialization logic.
-	/// </summary>
-	void Serialize(Save saveFile);
-
-	/// <summary>
-	/// Pure virtual function for loading data from a save file.<br/>
-	/// This will comprise the deserialziation logic.
-	/// </summary>
-	void Deserialize(Save saveFile);
-}

UOP1_Project/Assets/Scripts/SaveSystem/ISaveable.cs.meta

-fileFormatVersion: 2
-guid: ea156e29696b4339a873e00d168dd164
-timeCreated: 1613415034

UOP1_Project/Assets/Scripts/SaveSystem/Database.cs

-using System.Collections.Generic;
-using UnityEngine;
-
-public abstract class Database<T> : ScriptableObject where T : IDesc
-{
-	[SerializeField] protected List<T> _descs = new List<T>();
-
-	public virtual object FindByUuid(string uuid)
-	{
-		foreach (var desc in _descs)
-		{
-			if (desc.DescId.uuid == uuid)
-			{
-				return desc;
-			}
-		}
-
-		return null;
-	}
-}

UOP1_Project/Assets/Scripts/SaveSystem/Database.cs.meta

-fileFormatVersion: 2
-guid: 6f858bf525be0ea4986d5763b2261cb4
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

UOP1_Project/Assets/Scripts/SaveSystem/Editor.meta

-fileFormatVersion: 2
-guid: 95e496228d41fe8438f7ab581da0999d
-folderAsset: yes
-DefaultImporter:
-  externalObjects: {}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

UOP1_Project/Assets/Scripts/SaveSystem/IDesc.cs

-public interface IDesc
-{
-	Uuid DescId { get; }
-}

UOP1_Project/Assets/Scripts/SaveSystem/IDesc.cs.meta

-fileFormatVersion: 2
-guid: 6331f8f1642080c41b7bd5867823fe23
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

UOP1_Project/Assets/Scripts/SaveSystem/LocationDatabase.cs

-public class LocationDatabase : Database<LocationSO> { }

UOP1_Project/Assets/Scripts/SaveSystem/LocationDatabase.cs.meta

-fileFormatVersion: 2
-guid: a07abb7875a4fc945b9a7cf5212ed565
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

UOP1_Project/Assets/Scripts/SaveSystem/Uuid.cs

-[System.Serializable]
-public class Uuid
-{
-	public string uuid;
-
-	public static Uuid Generate()
-	{
-		Uuid newUuid = new Uuid { uuid = System.Guid.NewGuid().ToString() };
-		return newUuid;
-	}
-}

UOP1_Project/Assets/Scripts/SaveSystem/Uuid.cs.meta

-fileFormatVersion: 2
-guid: 212c6e5308f8ab845b25793c5ca1f413
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: