Create benchmark client and server for Node Express

package.json

src/node/performance/benchmark_client_express.js

src/node/performance/benchmark_server.js

src/node/performance/benchmark_server_express.js

src/node/performance/worker.js

src/node/performance/worker_service_impl.js

tools/run_tests/performance/scenario_config.py

tools/run_tests/run_tests.py