feat: Add transparent textures for storage overlay

src/main/resources/assets/firmament/textures/gui/sprites/storageoverlay/scroll_bar_background_1.png.mcmeta

@@ -0,0 +1,10 @@
+{
+    "gui": {
+        "scaling": {
+            "type": "nine_slice",
+            "width": 17,
+            "height": 18,
+            "border": 2
+        }
+    }
+}

src/main/resources/assets/firmament/textures/gui/sprites/storageoverlay/storage_controls_1.png.mcmeta

@@ -0,0 +1,10 @@
+{
+    "gui": {
+        "scaling": {
+            "type": "nine_slice",
+            "width": 91,
+            "height": 184,
+            "border": 7
+        }
+    }
+}

src/main/resources/assets/firmament/textures/gui/sprites/storageoverlay/storage_row_1.png.mcmeta

@@ -0,0 +1,9 @@
+{
+    "gui": {
+        "scaling": {
+            "type": "tile",
+            "width": 162,
+            "height": 18
+        }
+    }
+}

src/main/resources/assets/firmament/textures/gui/sprites/storageoverlay/upper_background_1.png.mcmeta

@@ -0,0 +1,10 @@
+{
+    "gui": {
+        "scaling": {
+            "type": "nine_slice",
+            "width": 176,
+            "height": 222,
+            "border": 10
+        }
+    }
+}