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