feat(cli): introduce tosa-converter-for-tflite CLI, tests, and docs

- Add `tosa_converter_for_tflite/cli.py` implementing the new CLI entrypoint
- Register CLI script in `setup.py` under `tosa-converter-for-tflite`
- Add new test definitions in `tests/test_cli.hjson` and runner in `tests/test_cli.py`
- Add tests README in `tests/README.md`
- Configure pytest in `setup.cfg` (testpaths, markers, python_files, norecursedirs)
- Update `.pre-commit-config.yaml` with `pytest-pre-commit` hook for `pre_commit` marked tests
- Extend project `README.md` with CLI usage and streaming examples

Signed-off-by: Deeptanshu Sekhri <deeptanshu.sekhri@arm.com>