Item sets now appear and can be unpacked at the GE

Added a proper mock session that gets used for mock players in unit tests. Allows verifying that certain packets made it to the IoSession (the stage right before sending it to the client)

Server/src/main/kotlin/rs09/game/interaction/inter/ge/ExchangeItemSets.kt

@@ -15,12 +15,6 @@ import rs09.game.interaction.InterfaceListener
 
 class ExchangeItemSets : InterfaceListener {
     override fun defineInterfaceListeners() {
-        onOpen(Components.EXCHANGE_ITEMSETS_645) { player, _ ->
-            val listener: InventoryListener
-            setAttribute(player, "ge-listener", InventoryListener(player).also { listener = it })
-            player.inventory.listeners.add(listener)
-        }
-
         onClose(Components.EXCHANGE_ITEMSETS_645){player, _ ->
             val listener = getAttribute<InventoryListener?>(player, "ge-listener", null)
             player.inventory.listeners.remove(listener)
@@ -37,6 +31,9 @@ class ExchangeItemSets : InterfaceListener {
         {
             openInterface(player, Components.EXCHANGE_ITEMSETS_645)
             player.interfaceManager.openSingleTab(Component(Components.EXCHANGE_SETS_SIDE_644))
+            val listener: InventoryListener
+            setAttribute(player, "ge-listener", InventoryListener(player).also { listener = it })
+            player.inventory.listeners.add(listener)
         }
     }
 
@@ -62,9 +59,9 @@ class ExchangeItemSets : InterfaceListener {
                             player.inventory.toArray(),
                             arrayOf("Examine", "Exchange", "Components"),
                             Components.EXCHANGE_SETS_SIDE_644,
-                            16,
-                            15,
-                            10
+                            0,
+                            7,
+                            4
                     )
             )