Research on serving RViz2 on web template

• omni-rviz2: Last updated in 2019. Stale repository.
• GitHub issue on official ROS2 RViz repo: Opened 3 days back. No responses till now.
  Update: Additional response which mentions Zethus (added below)
• Incorporating RViz2 into custom GUI (Qt app) led to this PR
• ROS visualization_tutorials issue: Not useful
• (Update) Zethus: Implements RViz in JS + ThreeJS
• (Update) Rosboard: Introduced in this ROS Discourse post

Serving RViz via VNC appears to be the most promising method