Fix onboarding OAuth callback glitch (#1079)

pages/api/integrations/utils.ts

@@ -0,0 +1,21 @@
+import { NextApiRequest } from "next";
+
+import { IntegrationOAuthCallbackState } from "./types";
+
+export function encodeOAuthState(req: NextApiRequest) {
+  if (typeof req.query.state !== "string") {
+    return undefined;
+  }
+  const state: IntegrationOAuthCallbackState = JSON.parse(req.query.state);
+
+  return JSON.stringify(state);
+}
+
+export function decodeOAuthState(req: NextApiRequest) {
+  if (typeof req.query.state !== "string") {
+    return undefined;
+  }
+  const state: IntegrationOAuthCallbackState = JSON.parse(req.query.state);
+
+  return state;
+}