idz: Hoist userdb code

src/idz/userdb/decoder/loadStocker.ts

@@ -0,0 +1,12 @@
+import { LoadStockerRequest } from "../request/loadStocker";
+import { AimeId } from "../../../model";
+
+loadStocker.msgCode = 0x00a7;
+loadStocker.msgLen = 0x0010;
+
+export function loadStocker(buf: Buffer): LoadStockerRequest {
+  return {
+    type: "load_stocker_req",
+    aimeId: buf.readUInt32LE(0x0004) as AimeId,
+  };
+}