Test cp/dp split

[kate-osborn]

Parent ticket: #292

Manually verify the following:

• The data plane can scale up and scale down
• The data plane and control plane connections are resilient:
  • data plane can handle a control plane restart event
  • control plane can handle a data plane restart event
  • data plane retries connecting to control plane after failure
  • data plane does not produce bad nginx config if a failure occurs while downloading config from control plane
• The data plane can handle frequent configuration changes (1 change per second)
• The data plane can handle large configurations:
  • 5000 server blocks
  • 64 TLS certs/keys
  • 50 JWT keys
  • 50 TLS cert/keys for egress
  • 50 CA certs
  • 50 basic auth files
  • 50 OIDC secrets

When possible, write unit tests or benchmark tests for these cases.

Aha! Link: https://nginx.aha.io/features/NKG-40