chunithm: Initial implementation code drop

No cleaner development history than this exists. It's difficult to
methodically design something when you don't yet know what it is
you're designing.

src/chunithm/handler/upsertClientError.ts

@@ -0,0 +1,12 @@
+import { Repositories } from "../repo";
+import { UpsertClientErrorRequest } from "../request/upsertClientError";
+import { UpsertClientErrorResponse } from "../response/upsertClientError";
+
+export default async function upsertClientError(
+  rep: Repositories,
+  req: UpsertClientErrorRequest
+): Promise<UpsertClientErrorResponse> {
+  return {
+    returnCode: "1",
+  };
+}