idz: Add UpdateExpedition command

src/idz/userdb/encoder/updateExpedition.ts

@@ -0,0 +1,18 @@
+import { UpdateExpeditionResponse } from "../response/updateExpedition";
+
+export function updateExpedition(res: UpdateExpeditionResponse) {
+  let buf: Buffer;
+
+  if (res.expeditionType == 0) {
+    buf = Buffer.alloc(0x0040);
+    buf.writeInt16LE(1, 0x0000);
+  } else {
+    buf = Buffer.alloc(0x19f0);
+    buf.writeInt16LE(0x0140, 0x0000);
+    // Experiments used to live here, removed because they're a not-really
+    // working mess. Hopefully, one day there will be beautiful code
+    // here, that works and makes people happy. One day.
+  }
+
+  return buf;
+}