Implement interfaces of various GUI windows (double chests, anvil, et…

…c) and fix NBT/missing packet crashes (#196)

* Implement double chests

* Implement Generic_9x4 and Generic_9x5

* Implement generic_9x1

* Fix generic_9x1's positioning and implement generic_9x2

* Refactor names, fix some formatting.

* Remove forgotten comment

* Fix NBT related crash

* Add missing packet

* Prepare for other interfaces

* Implement anvil ui

* Implement dropper & beacon

* Implement furnace, blast furnace, smoker

* Implement beacon

---------

Co-authored-by: stackotter <stackotter@stackotter.dev>

Sources/Core/Sources/Datatypes/NBT/NBTCompound.swift

@@ -138,7 +138,7 @@ extension NBT {
         case .end:
           break
         case .byte:
-          value = try buffer.readByte()
+          value = try buffer.readSignedByte()
         case .short:
           value = try buffer.readSignedShort(endianness: .big)
         case .int:

Sources/Core/Sources/GUI/GUISprite.swift

@@ -16,11 +16,23 @@ public enum GUISprite {
   case xpBarForeground
   case inventory
   case craftingTable
-  /// If positioned directly above ``GUISprite/singleChestBottomHalf`` it forms
+  case furnace
+  case blastFurnace
+  case smoker
+  case anvil
+  case dispenser
+  case beacon
+
+  /// If positioned directly above ``GUISprite/genericInventory`` it forms
   /// the background for a single chest window. The way the texture is made forces
   /// these to be separate sprites.
-  case singleChestTopHalf
-  case singleChestBottomHalf
+  case genericInventory // Inventory for most interfaces, its a part of the sprite
+  case generic9x1
+  case generic9x2
+  case generic9x3
+  case generic9x4
+  case generic9x5
+  case generic9x6
 
   case pinkBossBarBackground
   case pinkBossBarForeground
@@ -81,10 +93,32 @@ public enum GUISprite {
         return GUISpriteDescriptor(slice: .inventory, position: [0, 0], size: [176, 166])
       case .craftingTable:
         return GUISpriteDescriptor(slice: .craftingTable, position: [0, 0], size: [176, 166])
-      case .singleChestTopHalf:
-        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 71])
-      case .singleChestBottomHalf:
+      case .furnace:
+        return GUISpriteDescriptor(slice: .furnace, position: [0, 0], size: [176, 166])
+      case .blastFurnace:
+        return GUISpriteDescriptor(slice: .blastFurnace, position: [0, 0], size: [176, 166])
+      case .smoker:
+        return GUISpriteDescriptor(slice: .smoker, position: [0, 0], size: [176, 166])
+      case .anvil:
+        return GUISpriteDescriptor(slice: .anvil, position: [0, 0], size: [176, 166])
+      case .dispenser:
+        return GUISpriteDescriptor(slice: .dispenser, position: [0, 0],  size: [176, 166])
+      case .beacon:
+        return GUISpriteDescriptor(slice: .beacon, position: [0,0], size: [229, 218])
+      case .genericInventory:
         return GUISpriteDescriptor(slice: .genericContainer, position: [0, 125], size: [176, 97])
+      case .generic9x1:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 35])
+      case .generic9x2:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 53])
+      case .generic9x3:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 71])
+      case .generic9x4:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 89])
+      case .generic9x5:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 107])
+      case .generic9x6:
+        return GUISpriteDescriptor(slice: .genericContainer, position: [0, 0], size: [176, 222])
       case .pinkBossBarBackground:
         return GUISpriteDescriptor(slice: .bars, position: [0, 0], size: [182, 5])
       case .pinkBossBarForeground: