Scale testing for delegate runner

This utility provide an easy way to scale test runner. Scale test can be done on a specific infra or completely on local using noop driver. Noop driver simulates the vm operations.

How to scale test using noop driver:

1. Start the lite-engine on local in insecure mode using using: SERVER_INSECURE=true go run main.go server
2. Update the endpoint of lite-engine manually to http from https in checkInstanceConnectivity (manager.go file) & GetClient (lehelper.go file). This is required for runner to connect to lite-engine on local.
3. Use a noop driver in pool.yml: `instances:
   • name: test-noop default: true type: noop pool: 20 # total number of warm instances in the pool at all times limit: 100 # limit the total number of running servers. If exceeded block or error. platform: os: linux arch: arm64 spec: hibernate: false`
4. Start the delegate runner using: go run main.go delegate --pool=pool.yml
5. Run the scale test on runner using: go run main.go tester --pool=test-noop --scale=10. Here pool is the name of the pool on which scale testing will happen and scale is number of parallel builds to run.