Added more slot builders

eco-api/src/main/kotlin/com/willfp/eco/core/gui/GUIHelpers.kt

@@ -6,38 +6,29 @@ import com.willfp.eco.core.gui.menu.Menu
 import com.willfp.eco.core.gui.menu.MenuBuilder
 import com.willfp.eco.core.gui.slot.Slot
 import com.willfp.eco.core.gui.slot.SlotBuilder
+import com.willfp.eco.core.items.TestableItem
 import org.bukkit.entity.Player
 import org.bukkit.event.inventory.InventoryClickEvent
 import org.bukkit.event.inventory.InventoryCloseEvent
 import org.bukkit.inventory.ItemStack
 
-/**
- * @see SlotBuilder.onLeftClick
- */
+/** @see SlotBuilder.onLeftClick */
 fun SlotBuilder.onLeftClick(action: (InventoryClickEvent, Slot, Menu) -> Unit): SlotBuilder =
     this.onLeftClick { a, b, c -> action(a, b, c) }
 
-/**
- * @see SlotBuilder.onRightClick
- */
+/** @see SlotBuilder.onRightClick */
 fun SlotBuilder.onRightClick(action: (InventoryClickEvent, Slot, Menu) -> Unit): SlotBuilder =
     this.onRightClick { a, b, c -> action(a, b, c) }
 
-/**
- * @see SlotBuilder.onShiftLeftClick
- */
+/** @see SlotBuilder.onShiftLeftClick */
 fun SlotBuilder.onShiftLeftClick(action: (InventoryClickEvent, Slot, Menu) -> Unit): SlotBuilder =
     this.onShiftLeftClick { a, b, c -> action(a, b, c) }
 
-/**
- * @see SlotBuilder.onShiftRightClick
- */
+/** @see SlotBuilder.onShiftRightClick */
 fun SlotBuilder.onShiftRightClick(action: (InventoryClickEvent, Slot, Menu) -> Unit): SlotBuilder =
     this.onShiftRightClick { a, b, c -> action(a, b, c) }
 
-/**
- * @see SlotBuilder.onShiftRightClick
- */
+/** @see SlotBuilder.onShiftRightClick */
 fun SlotBuilder.onMiddleClick(action: (InventoryClickEvent, Slot, Menu) -> Unit): SlotBuilder =
     this.onMiddleClick { a, b, c -> action(a, b, c) }
 
@@ -50,20 +41,32 @@ fun SlotBuilder.onMiddleClick(action: (InventoryClickEvent, Slot, Menu) -> Unit)
 fun SlotBuilder.setModifier(action: (Player, Menu, ItemStack) -> Unit): SlotBuilder =
     this.setUpdater { a, b, c -> c.apply { action(a, b, c) } }
 
-/**
- * @see SlotBuilder.setUpdater
- */
+/** @see SlotBuilder.setUpdater */
 fun SlotBuilder.setUpdater(action: (Player, Menu, ItemStack) -> ItemStack): SlotBuilder =
     this.setUpdater { a, b, c -> action(a, b, c) }
 
-/**
- * Kotlin builder for slots.
- */
+/** Kotlin builder for slots. */
 fun captiveSlot(): Slot = Slot.builder().setCaptive().build()
 
-/**
- * Kotlin builder for slots.
- */
+/** Kotlin builder for slots. */
+fun captiveSlot(
+    init: SlotBuilder.() -> Unit
+): Slot {
+    val builder = Slot.builder().setCaptive()
+    init(builder)
+    return builder.build()
+}
+
+/** Kotlin builder for slots. */
+fun slot(
+    init: SlotBuilder.() -> Unit
+): Slot {
+    val builder = Slot.builder()
+    init(builder)
+    return builder.build()
+}
+
+/** Kotlin builder for slots. */
 fun slot(
     item: ItemStack,
     init: SlotBuilder.() -> Unit
@@ -73,16 +76,17 @@ fun slot(
     return builder.build()
 }
 
-/**
- * Kotlin builder for slots.
- */
+/** Kotlin builder for slots. */
 fun slot(
     item: ItemStack
 ): Slot = Slot.builder(item).build()
 
-/**
- * Kotlin builder for slots.
- */
+/** Kotlin builder for slots. */
+fun slot(
+    item: TestableItem
+): Slot = Slot.builder(item.item).build()
+
+/** Kotlin builder for slots. */
 fun slot(
     provider: (Player, Menu) -> ItemStack,
     init: SlotBuilder.() -> Unit
@@ -92,34 +96,24 @@ fun slot(
     return builder.build()
 }
 
-/**
- * Kotlin builder for slots.
- */
+/** Kotlin builder for slots. */
 fun slot(
     provider: (Player, Menu) -> ItemStack
 ): Slot = Slot.builder { a, b -> provider(a, b) }.build()
 
-/**
- * @see MenuBuilder.onClose
- */
+/** @see MenuBuilder.onClose */
 fun MenuBuilder.onClose(action: (InventoryCloseEvent, Menu) -> Unit): MenuBuilder =
     this.onClose { a, b -> action(a, b) }
 
-/**
- * @see MenuBuilder.modify
- */
+/** @see MenuBuilder.modify */
 fun MenuBuilder.modify(modifier: (MenuBuilder) -> Unit): MenuBuilder =
     this.modfiy { modifier(it) }
 
-/**
- * @see MenuBuilder.onRender
- */
+/** @see MenuBuilder.onRender */
 fun MenuBuilder.onRender(action: (Player, Menu) -> Unit): MenuBuilder =
     this.onRender { a, b -> action(a, b) }
 
-/**
- * Kotlin builder for menus.
- */
+/** Kotlin builder for menus. */
 fun menu(
     rows: Int,
     init: MenuBuilder.() -> Unit