Restore particle cloud visualization using markers

[hidmic]

Proposed changes

Follow-up to #372. As the title reads, this restores the functionality we had with nav2_msgs/ParticleCloud using visualization_msgs/MarkerArray instead.

particle_markers.opt.mp4

Type of change

• 🐛 Bugfix (change which fixes an issue)
• 🚀 Feature (change which adds functionality)
• 📚 Documentation (change which fixes or extends documentation)

Checklist

• Lint and unit tests (if any) pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• All commits have been signed for DCO

[nahueespinosa]

LGTM!