chore(server): split gcloud sql proxy into a separate deployment (#5101)

After merge this pull request, need to change the `DATABASE_URL` in environment secrets (stable/beta) from `127.0.0.1` to `affine-cloud-sql-proxy`

.github/helm/affine/values.yaml

@@ -16,6 +16,8 @@ global:
       cloudSqlInternal: ''
       connectionName: ''
       serviceAccount: ''
+      cloudProxyReplicas: 3
+      proxyPort: '5432'
   redis:
     enabled: true
     host: 'redis-master'