Improve Graphql Performance and Scalability

[Niicck]

• [x] Maintain individual postgres connection pools of size 1 on every graphql lambda function.
• [ ] Place graphql lambda functions in the same VPC as postgres RDS.

[Niicck]

• [ ] add a cost analysis limit to graphql queries
• [ ] add a concurrency limit (via API Gateway, preferably) to /graphql endpoints
• [ ] experiment with larger DB instances, for better bandwidth

[Niicck]

current working branch is "load-test"

[Niicck]

• [ ] experiment with SSD
• [ ] experiment with Provisioned iOps