Set up prettier + eslint

- Add npm scripts format:check, format:fix, lint:check, lint:fix
- Include format:check + lint:check into the test suite (test:all)
- Configure eslint to play nice with prettier (basically no format checks)

Test: npm run format:check && npm run lint:check
Bug: b/263471740
Change-Id: I6f215860a24302ed04c2689ac31e4dd4e7e6fd5e
4 files changed