Improve sample/tutorial testing
- [X] Enable golden image validation on GitHub CI
- [X] Enable golden image validation on Linux
- [X] Add golden images for new tutorials
- [X] Move golden images to LFS (avoid keeping binary files in git history)
- [ ] Capture/compare golden images at specific time (e.g. 2 seconds) (avoid bugs such as https://github.com/DiligentGraphics/DiligentSamples/commit/4e4a268a31619bd782beefc63b20923430fdb617)
- [ ] Implement capturing/comparing multiple golden images with different settings