add RPC for decayTokensOfCharacter

src/backend/Components/Item/ItemManager.ts

         RPCs: () => [
             this.wipeCurrencyAndItems
         ]
+    },{
+        name: 'decay' as 'decay',
+        RPCs: () => [
+            this.decayTokensOfCharacter
+        ]
     }]
 
     notifyRaid = async (raid: Raid | { id: number }) => {

src/backend/Components/Item/RPCInterface.ts

         setPriority:IItemManager['setPriority']
         deletePriority: IItemManager['deletePriority']
     }
+    decay: {
+        decayTokensOfCharacter: IItemManager['decayTokensOfCharacter']
+    }
 }