[BUG] Error in POV-RAY output generated from Project Chrono Demo

[Autonomousanz]

Summary

The render_frames.pov generated after running the POV-ray demo file from the project chrono build has many issues to name a few:

1. On running the demo_POST_povray from build chrono has Segmentation fault (core dumped) issue when running on ubuntu 20.4 with POV-Ray 3.7.0.8(g++ @ x86_64-pc-linux-gnu).
2. The same demo running in ubuntu20.4 based docker image generated output files of stateXXXXX.pov files however while running the render_frames.pov, it is looking for bluewhite. file instead of bluewhite.png in textures folder

Even after placing a dummy bluewhite. dummy file it throws other error