feat(search): handle search indexing coordination among nodes

Signed-off-by: Phil Kuang <pkuang@factset.com>

packages/backend/package.json

@@ -68,6 +68,7 @@
     "express": "^4.17.1",
     "express-promise-router": "^4.1.0",
     "express-prom-bundle": "^6.3.6",
+    "luxon": "^2.0.2",
     "pg": "^8.3.0",
     "pg-connection-string": "^2.3.0",
     "prom-client": "^14.0.1",
@@ -77,7 +78,8 @@
     "@backstage/cli": "^0.17.0-next.1",
     "@types/dockerode": "^3.3.0",
     "@types/express": "^4.17.6",
-    "@types/express-serve-static-core": "^4.17.5"
+    "@types/express-serve-static-core": "^4.17.5",
+    "@types/luxon": "^2.0.4"
   },
   "files": [
     "dist"