feat(clients): professional clients with tests, CI/CD, and examples

- Python: pyproject.toml, pytest suite (unit + integration), README, examples
- JavaScript: package.json, TypeScript definitions, node:test suite, README, examples
- Nim: integration tests, examples, README, improved nimble tasks
- Rust: fixed nodelay/localhost IPv6 bug, integration tests, examples, README
- Added GitHub Actions CI for all 4 clients against Docker server
- Added docker-compose.test.yml for local integration testing
- Added .gitignore for each client

clients/javascript/.gitignore

@@ -0,0 +1,9 @@
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+package-lock.json
+*.log
+.DS_Store
+coverage/
+.nyc_output/