feature: add mailbox naming for shipping labels

elements/MailboxNameEntryGUI.mod.json

@@ -0,0 +1,69 @@
+{
+  "_fv": 73,
+  "_type": "gui",
+  "definition": {
+    "type": 0,
+    "width": 176,
+    "height": 166,
+    "inventoryOffsetX": 0,
+    "inventoryOffsetY": 0,
+    "renderBgLayer": false,
+    "doesPauseGame": false,
+    "components": [
+      {
+        "type": "label",
+        "data": {
+          "name": "label_mailbox_name",
+          "text": {
+            "fixedValue": "Mailbox Name:"
+          },
+          "color": {
+            "value": -16724839,
+            "falpha": 0.0
+          },
+          "x": 177,
+          "y": 85,
+          "locked": false
+        }
+      },
+      {
+        "type": "textfield",
+        "data": {
+          "placeholder": "",
+          "name": "mailbox_name_field",
+          "width": 120,
+          "height": 20,
+          "x": 155,
+          "y": 98,
+          "locked": false
+        }
+      },
+      {
+        "type": "button",
+        "data": {
+          "name": "button_done",
+          "text": "Done",
+          "isUndecorated": false,
+          "onClick": {
+            "name": "MailboxNameEntryButtonPressed"
+          },
+          "width": 46,
+          "height": 20,
+          "x": 191,
+          "y": 130,
+          "locked": false
+        }
+      }
+    ],
+    "onClosed": {
+      "name": "MailboxNameEntryGUIThisGUIIsClosed"
+    },
+    "gridSettings": {
+      "sx": 9,
+      "sy": 9,
+      "ox": 11,
+      "oy": 15,
+      "snapOnGrid": true
+    }
+  }
+}