tools: update ci.py to match Gitlab CI pipeline

This change restores and modernizes tools/ci.py to enable
developers to run all public CI checks locally, consistent
with the current Gitlab CI pipeline.

- Added support for all relevant code-quality checks.
- Integrated product build support using check_build.build_products()
- Added stage-based execution:
	--stage code-quality, unit-testing, build, or all

Signed-off-by: Mahmoud Elsabbagh <mahmoud.elsabbagh@arm.com>