loot tracker: store loot in config

Since loot is now aggregated, the data is little enough to store in
config. This allows loot to persist between sessions even when not
logged in.

runelite-client/src/test/java/net/runelite/client/plugins/loottracker/LootTrackerPluginTest.java

@@ -55,6 +55,7 @@ import net.runelite.api.widgets.WidgetID;
 import net.runelite.client.account.SessionManager;
 import net.runelite.client.chat.ChatMessageManager;
 import net.runelite.client.chat.QueuedMessage;
+import net.runelite.client.config.ConfigManager;
 import net.runelite.client.game.ItemManager;
 import net.runelite.client.game.ItemStack;
 import net.runelite.client.game.SpriteManager;
@@ -139,6 +140,10 @@ public class LootTrackerPluginTest
 	@Bind
 	private LootTrackerClient lootTrackerClient;
 
+	@Mock
+	@Bind
+	private ConfigManager configManager;
+
 	@Before
 	public void setUp()
 	{